Naltrexone extended-release plus bupropion extended-release for treatment of obesity

Obesity medications: A narrative review of current and emerging agents

The aim of this narrative review is to synthesize the available data describing the efficacy and safety of medications approved for obesity management and to provide an overview of upcoming agents in development. A literature search of PubMed, Medline, and Embase databases identified relevant articles describing medications approved in the U.S., Australia, U.K., and/or Europe. Papers were selected based on relevance and originality, with phase 3 clinical trials and meta-analyses preferentially included. Six medications are widely approved for long-term weight management in conjunction with lifestyle interventions in people with body mass index (BMI) ≥30 ​kg/m2 or BMI ≥27 ​kg/m2 and at least one medical condition related to excess weight. Compared with lifestyle interventions alone, all medications approved for obesity management are more effective for long-term weight loss and improvements in cardiometabolic risk factors. Older obesity medications are associated with mean weight losses in the range of 5-10%. The new generation of agents, including the injectable incretin analogues semaglutide and tirzepatide are associated with sustained mean weight reductions of 15-20%, along with substantial benefits on a range of health outcomes. Several novel agents are under development, with multi-hormone receptor agonists and oral formulations likely to become available in the coming years. As effective treatment options expand, cost and availability will need to be addressed to enable equitable access to treatment. Other important challenges for clinical practice and research include the need for long-term strategies to prevent and manage weight regain and loss of lean muscle and bone mineral density.

The effects of bupropion alone and combined with naltrexone on blood pressure and CRP concentration: A systematic review and meta-regression analysis of randomized controlled trials

BACKGROUND

Considering the conflicting effects of bupropion on parameters related to cardiovascular system including blood pressure and inflammation, in this meta-analysis study, we investigated the effects of this drug alone or in combination with naltrexone on systolic (SBP) and diastolic blood pressure (DBP) and C-reactive protein (CRP).

METHODS

Scopus, PubMed/Medline, Web of Science and Embase databases were searched using standard keywords to identify all controlled trials investigating effects of bupropion alone and combined with naltrexone on the BP and CRP. Pooled weighted mean difference and 95% confidence intervals (CIs) were achieved by random-effects model analysis for the best estimation of outcomes.

RESULTS

The pooled findings showed that that bupropion alone or in combination with naltrexone would significantly increase SBP (weighted mean difference (WMD): 1.34 mmHg, 95% CI: 0.38-2.29) and DBP (WMD: 0.93 mmHg, 95% CI 0.88-0.99) as well as decrease CRP (WMD: -0.89 mg/L, 95% CI -1.09 to -0.70). The findings of the subgroup also show the greater effect of bupropion on blood pressure (SBP and DBP) increase in a dose greater than 360 mg and a duration of intervention less equal to 26 weeks. In addition, the subgroup analysis showed that changes in SBP after receiving bupropion together with naltrexone were more compared to bupropion alone.

CONCLUSIONS

The addition of combination therapies such as bupropion and naltrexone can significantly improve CRP levels. However, its effect on blood pressure requires proper management of this drug.

The relation between excess adiposity and breast cancer in women: Clinical implications and management

BACKGROUND

Breast cancer (BC) is the most common cancer in women. While the combination of improved screening, earlier detection, and advances in therapeutics has resulted in lower BC mortality, BC survivors are now increasingly dying of cardiovascular disease. Cardiovascular disease in the leading cause of non-cancer related mortality among BC survivors. This situation underscores the critical need to research the role of modifiable cardiometabolic risk factors, such as excess adiposity, that will affect BC remission, long-term survivorship, and overall health and quality of life.

PURPOSE

First, this review summarizes the evidence on the connection between adipose tissue and BC. Then we review the data on weight trends after BC diagnosis with a focus on the effect of weight gain on BC recurrence and BC- and non-BC-related death. Finally, we provide a guide for weight management in BC survivors, considering the available data on the effect of weight loss interventions on BC.

Naltrexone plus bupropion combination medication maintenance treatment for binge-eating disorder following successful acute treatments: randomized double-blind placebo-controlled trial

BACKGROUND

Certain treatments have demonstrated acute efficacy for binge-eating disorder (BED) but there is a dearth of controlled research examining pharmacotherapies as maintenance treatments for responders to initial interventions. This gap in the literature is particularly critical for pharmacotherapy for BED which is associated with relapse following discontinuation. The current study tested the efficacy of naltrexone/bupropion maintenance treatment amongst responders to acute treatments for BED.

METHODS

Prospective randomized double-blind placebo-controlled single-site trial, conducted August 2017-December 2021, tested naltrexone/bupropion as maintenance treatment for responders to acute treatments with naltrexone/bupropion and/or behavioral weight-loss therapy for BED with comorbid obesity. Sixty-six patients (84.8% women, mean age 46.9, mean BMI 34.9 kg/m2) who responded to acute treatments were re-randomized to placebo (N = 34) or naltrexone/bupropion (N = 32) for 16 weeks; 86.3% completed posttreatment assessments. Mixed models and generalized estimating equations comparing maintenance treatments (naltrexone/bupropion v. placebo) included main and interactive effects of acute treatments.

RESULTS

Intention-to-treat binge-eating remission rates following maintenance treatments were 50.0% (N = 17/34) for placebo and 68.8% (N = 22/32) for naltrexone/bupropion. Placebo following response to acute treatment with naltrexone/bupropion was associated with significantly decreased probability of binge-eating remission, increased binge-eating frequency, and no weight loss. Naltrexone/bupropion following response to acute treatment with naltrexone/bupropion was associated with good maintenance of binge-eating remission, low binge-eating frequency, and significant additional weight loss.

CONCLUSIONS

Adult patients with BED with co-occurring obesity who have good responses to acute treatment with naltrexone/bupropion should be offered maintenance treatment with naltrexone/bupropion.

Naltrexone/bupropion for binge-eating disorder: A randomized, double-blind, placebo-controlled trial

OBJECTIVE

Binge-eating disorder (BED) is a prevalent psychiatric disorder associated with obesity. Few evidence-based treatments exist for BED, particularly pharmacological options. This study tested the efficacy of naltrexone/bupropion for BED.

METHODS

A randomized, double-blind, placebo-controlled, 12-week trial tested naltrexone/bupropion for BED with and without obesity. Eighty-nine patients (70.8% women, 69.7% White, mean age 45.7 y, mean BMI 35.1 kg/m2 , 77.5% with BMI ≥ 30 kg/m2 ) were randomized to placebo (n = 46) or naltrexone/bupropion (n = 43), with randomization stratified by obesity status and gender; 92.1% completed post-treatment assessments.

RESULTS

Mixed models of binge-eating frequency revealed significant reductions that did not differ significantly between naltrexone/bupropion and placebo. Logistic regression of binge-eating remission rates revealed that naltrexone/bupropion and placebo did not differ significantly. Obesity status did not predict, or moderate, binge-eating outcomes considered either continuously or categorically. Mixed models revealed that naltrexone/bupropion was associated with significantly greater percentage weight loss than placebo. Logistic regression revealed that naltrexone/bupropion had significantly higher rates of attaining ≥5% weight loss than placebo (27.9% vs. 6.5%). Obesity status did not predict or moderate weight-loss outcomes.

CONCLUSIONS

Naltrexone/bupropion did not demonstrate effectiveness for reducing binge eating relative to placebo but showed effectiveness for weight reduction in patients with BED. Obesity status did not predict or moderate medication outcomes.

Cognitive-behavioral therapy for binge-eating disorder for non-responders to initial acute treatments: Randomized controlled trial

OBJECTIVE

Certain treatments have demonstrated acute efficacy for binge-eating disorder (BED) but many patients who receive "evidence-based" interventions do not derive sufficient benefit. Given the dearth of controlled research examining treatments for patients who fail to respond to initial interventions, this study tested the efficacy of cognitive-behavioral therapy (CBT) for patients with BED who do not respond to initial acute treatments.

METHODS

Prospective randomized double-blind placebo-controlled single-site trial, conducted August 2017-December 2021, tested 16-weeks of therapist-led CBT for non-responders to initial treatment (naltrexone/bupropion and/or behavioral therapy) for BED with obesity. Thirty-one patients (mean age 46.3 years, 77.4% women, 80.6% White, mean BMI 38.99 kg/m2 ) who were non-responders to initial acute treatments were randomized to CBT (N = 18) or no-CBT (N = 13), in addition to continuing double-blinded pharmacotherapy. Independent assessments were performed at baseline, throughout treatment, and posttreatment; 83.9% completed posttreatment assessments.

RESULTS

Intention-to-treat remission rates were significantly higher for CBT (61.1%; N = 11/18) than no-CBT (7.7%; N = 1/13). Mixed models of binge-eating frequency (assessed using complementary methods) converged revealing a significant interaction between CBT and time and a significant main effect of CBT. Binge-eating frequency decreased significantly with CBT but did not change significantly with no-CBT. Since only four patients received behavioral treatment during the acute treatments, we performed "sensitivity-type" analyses restricted to the 27 patients who received pharmacotherapy during the acute treatment and found the same pattern of findings for CBT versus no-CBT.

CONCLUSIONS

Adult patients with BED who fail to respond to initial pharmacological treatments should be offered CBT.

PUBLIC SIGNIFICANCE

Even with leading evidence-based treatments for binge-eating disorder, many patients do not derive sufficient benefit. Almost no controlled research has examined treatments for patients who fail to respond to initial interventions. This study found that that cognitive-behavioral therapy was effective for patients with binge-eating disorder who did not respond to initial interventions, with 61% achieving abstinence.

Stereoselective Metabolism of Bupropion to Active Metabolites in Cellular Fractions of Human Liver and Intestine

Striking stereoselective disposition of the antidepressant and smoking cessation aid bupropion (BUP) and its active metabolites observed clinically influence patients' response to BUP therapy and its clinically important drug-drug interactions (DDI) with CYP2D6 substrates. However, understanding of the biochemical mechanisms responsible is incomplete. This study comprehensively examined hepatic and extrahepatic stereoselective metabolism of BUP in vitro Racemic-, R-, and S-BUP were incubated separately with pooled cellular fractions of human liver [microsomes (HLMs), S9 fractions (HLS9s), and cytosols (HLCs)] and intestinal [microsomes (HIMs), S9 fractions (HIS9s), and cytosols (HICs)] and cofactors. Formations of diastereomers of 4-hydroxyBUP (OHBUP), threohydroBUP (THBUP), and erythrohydroBUP (EHBUP) were quantified using a novel chiral ultra-high performance liquid chromatography/tandem mass spectrometry method. Racemic BUP (but not R- or S-BUP) was found suitable to determine stereoselective metabolism of BUP; both enantiomers showed complete racemization. Compared with that of RR-THBUP, the in vitro intrinsic clearance (Clint) for the formation of SS-THBUP was 42-, 19-, and 8.3-fold higher in HLMs, HLS9 fractions, and HLCs, respectively; Clint for the formation of SS-OHBUP and RS-EHBUP was also higher (2.7- to 3.9-fold) than their R-derived counterparts. In cellular fractions of human intestine, ≥ 95% of total reduction was accounted by the formation of RR-THBUP. Ours is the first to demonstrate marked stereoselective reduction of BUP in HLCs, HIMs, HIS9 fractions, and HICs, providing the first evidence for tissue- and cellular fraction-dependent stereoselective metabolism of BUP. These data may serve as the first critical step toward understanding factors dictating BUP's stereoselective disposition, effects, and DDI risks. SIGNIFICANCE STATEMENT: This work provides a deeper insight into bupropion (BUP) stereoselective oxidation and reduction to active metabolites in cellular fractions of human liver and intestine tissues. The results demonstrate tissue- and cellular fraction-dependent stereospecific metabolism of BUP. These data may improve prediction of BUP stereoselective disposition and understanding of BUP's effects and CYP2D6-dependent drug-drug interaction in vivo.

Naltrexone-Bupropion and Behavior Therapy, Alone and Combined, for Binge-Eating Disorder: Randomized Double-Blind Placebo-Controlled Trial

OBJECTIVE

Binge-eating disorder, the most prevalent eating disorder, is a serious public health problem associated with obesity, psychiatric and medical comorbidities, and functional impairments. Binge-eating disorder remains underrecognized and infrequently treated, and few evidence-based treatments exist. The authors tested the effectiveness of naltrexone-bupropion and behavioral weight loss therapy (BWL), alone and combined, for binge-eating disorder comorbid with obesity.

METHODS

In a randomized double-blind placebo-controlled trial conducted from February 2017 to February 2021, using a 2×2 balanced factorial design, 136 patients with binge-eating disorder (81.6% women; mean age, 46.5 years; mean BMI, 37.1) were randomized to one of four 16-week treatments: placebo (N=34), naltrexone-bupropion (N=32), BWL+placebo (N=35), or BWL+naltrexone-bupropion (N=35). Overall, 81.7% of participants completed independent posttreatment assessments.

RESULTS

Intention-to-treat binge-eating remission rates were 17.7% in the placebo group, 31.3% in the naltrexone-bupropion group, 37.1% in the BWL+placebo group, and 57.1% in the BWL+naltrexone-bupropion group. Logistic regression of binge-eating remission revealed that BWL was significantly superior to no BWL, and that naltrexone-bupropion was significantly superior to placebo, but there was no significant interaction between BWL and medication. Mixed models of complementary measures of binge-eating frequency also indicated that BWL was significantly superior to no BWL. The rates of participants attaining 5% weight loss were 11.8% in the placebo group, 18.8% in the naltrexone-bupropion group, 31.4% in the BWL+placebo group, and 38.2% in the BWL+naltrexone-bupropion group. Logistic regression of 5% weight loss and mixed models of percent weight loss both revealed that BWL was significantly superior to no BWL. Mixed models revealed significantly greater improvements for BWL than no BWL on secondary measures (eating disorder psychopathology, depression, eating behaviors, and cholesterol and HbA1c levels).

CONCLUSIONS

BWL and naltrexone-bupropion were associated with significant improvements in binge-eating disorder, with a consistent pattern of BWL being superior to no BWL.

Pharmacologic Weight Management in the Era of Adolescent Obesity

CONTEXT

Pediatric obesity is a serious health problem in the United States. While lifestyle modification therapy with dietary changes and increased physical activity are integral for the prevention and treatment of mild to moderate obesity in youth, only a modest effect on sustained weight reduction is observed in children and young adults with severe obesity. This underscores the need for additional evidence-based interventions for children and adolescents with severe obesity, including pharmacotherapy, before considering invasive procedures such as bariatric surgery.

EVIDENCE ACQUISITION

This publication focuses on recent advances in pharmacotherapy of obesity with an emphasis on medications approved for common and rarer monogenic forms of pediatric obesity.

EVIDENCE SYNTHESIS

We review medications currently available in the United States, both those approved for weight reduction in children and "off-label" medications that have a broad safety margin.

CONCLUSION

It is intended that this review will provide guidance for practicing clinicians and will encourage future exploration for successful pharmacotherapy and other interventions for obesity in youth.

Signaling pathways in obesity: mechanisms and therapeutic interventions

Obesity is a complex, chronic disease and global public health challenge. Characterized by excessive fat accumulation in the body, obesity sharply increases the risk of several diseases, such as type 2 diabetes, cardiovascular disease, and nonalcoholic fatty liver disease, and is linked to lower life expectancy. Although lifestyle intervention (diet and exercise) has remarkable effects on weight management, achieving long-term success at weight loss is extremely challenging, and the prevalence of obesity continues to rise worldwide. Over the past decades, the pathophysiology of obesity has been extensively investigated, and an increasing number of signal transduction pathways have been implicated in obesity, making it possible to fight obesity in a more effective and precise way. In this review, we summarize recent advances in the pathogenesis of obesity from both experimental and clinical studies, focusing on signaling pathways and their roles in the regulation of food intake, glucose homeostasis, adipogenesis, thermogenesis, and chronic inflammation. We also discuss the current anti-obesity drugs, as well as weight loss compounds in clinical trials, that target these signals. The evolving knowledge of signaling transduction may shed light on the future direction of obesity research, as we move into a new era of precision medicine.

Prader–Willi Syndrome: Possibilities of Weight Gain Prevention and Treatment

Prader–Willi syndrome (PWS) is a complex genetic disorder which involves the endocrine and neurologic systems, metabolism, and behavior. The aim of this paper is to summarize current knowledge on dietary management and treatment of PWS and, in particular, to prevent excessive weight gain. Growth hormone (GH) therapy is the recommended standard treatment for PWS children, because it improves body composition (by changing the proportion of body fat and lean body mass specifically by increasing muscle mass and energy expenditure), linear growth, and in infants, it promotes psychomotor and IQ development. In early childhood, the predominant symptom is hyperphagia which can lead to early onset, severe obesity with different obesity-related comorbidities. There are several studies on anti-obesity medications (metformin, topiramate, liraglutide, setmelanotide). However, these are still limited, and no widely accepted consensus guideline exists concerning these drugs in children with PWS. Until there is a specific treatment for hyperphagia and weight gain, weight must be controlled with the help of diet and exercise. Below the age of one year, children with PWS have no desire to eat and will often fail to thrive, despite adequate calories. After the age of two years, weight begins to increase without a change in calorie intake. Appetite increases later, gradually, and becomes insatiable. Managing the progression of different nutritional phases (0–4) is really important and can delay the early onset of severe obesity. Multidisciplinary approaches are crucial in the diagnosis and lifelong follow-up, which will determine the quality of life of these patients.

Integrative Hedonic and Homeostatic Food Intake Regulation by the Central Nervous System: Insights from Neuroimaging

Food intake regulation in humans is a complex process controlled by the dynamic interaction of homeostatic and hedonic systems. Homeostatic regulation is controlled by appetitive signals from the gut, adipose tissue, and the vagus nerve, while conscious and unconscious reward processes orchestrate hedonic regulation. On the one hand, sight, smell, taste, and texture perception deliver potent food-related feedback to the central nervous system (CNS) and influence brain areas related to food reward. On the other hand, macronutrient composition stimulates the release of appetite signals from the gut, which are translated in the CNS into unconscious reward processes. This multi-level regulation process of food intake shapes and regulates human ingestive behavior. Identifying the interface between hormones, neurotransmitters, and brain areas is critical to advance our understanding of conditions like obesity and develop better therapeutical interventions. Neuroimaging studies allow us to take a glance into the central nervous system (CNS) while these processes take place. This review focuses on the available neuroimaging evidence to describe this interaction between the homeostatic and hedonic components in human food intake regulation.

Use of prescription medications associated with weight gain among US adults, 1999-2018: A nationally representative survey

OBJECTIVE

This study aimed to evaluate trends in the use of obesogenic medications among adults.

METHODS

Cross-sectional data on adults aged ≥20 years are from the 1999 to 2018 National Health and Nutrition Examination Survey (n = 52,340). Obesogenic medications were defined according to the 2015 Endocrine Society guidelines on the pharmacological management of obesity. Weight status was categorized according to BMI. Trends in prior 30-day use were evaluated.

RESULTS

In NHANES 2017-2018, 20.3% of US adults used an obesogenic medication. Beta-blockers (9.8%) and antidiabetics (5.7%) were the most common; antipsychotics (1.0%) were the least common. Most common indications were disorders of glucose metabolism, hypertension, neuralgia or neuritis, heart disease, and musculoskeletal pain and/or inflammation. From 1999 to 2018, the proportional use of obesogenic medications increased for anticonvulsants (34.4% to 55.0%) but decreased for antidepressants (32.1% to 18.8%), antidiabetics (82.9% to 52.5%), and beta-blockers (83.9% to 80.7%). The proportional use of obesogenic medications was not associated with weight status, except for antipsychotics.

CONCLUSIONS

Use of obesogenic medications was common. Differences in the proportional use of obesogenic medication may reflect changing availability of obesogenic versus nonobesogenic medications over time. The decision to prescribe a nonobesogenic alternative, if one exists, is guided by weighing the risks and benefits of available treatments.

Integrating semaglutide into obesity management - a primary care perspective

This final article in the supplement aims to summarize a clinical approach for weight management geared toward primary care practitioners, offering practical advice about how to integrate weight management into day-to-day practice. To achieve long-term successful weight loss, a comprehensive multimodal approach is recommended, focusing on both lifestyle modification and appropriate use of therapy. Once-weekly subcutaneous semaglutide 2.4 mg is a novel treatment that can be used as an adjunct to lifestyle modification for the management of overweight and obesity. Key considerations are presented to support its optimal administration in conjunction with lifestyle modification, with a focus on assessing suitability and the importance of dose escalation and monitoring.

Anti-Obesity Medication Use in Children and Adolescents with Prader-Willi Syndrome: Case Review and Literature Search

(1) Background: children with Prader-Willi syndrome (PWS) have high obesity rates due to hyperphagia and decreased metabolic rates. Although anti-obesity medications (AOMs) are prescribed to this population, there are no consensus guidelines on acceptability, safety, and efficacy. We present literature review and case series on AOMs in youth with PWS. (2) Methods: we performed PubMed review from January 2000 to April 2021 utilizing keywords: "Prader-Willi syndrome" or "PWS" and "medication" including: topiramate, metformin, phentermine, liraglutide, orlistat, oxytocin, semaglutide, naltrexone-bupropion. For our case series, patients were identified through retrospective chart reviews from a multi-disciplinary PWS clinic. Eligibility criteria: age ≤ 18 years, genetically confirmed PWS, AOM use for at least 16 weeks, and recent anthropometric data. (3) Results: a literature search yielded 14 articles (3 topiramate, 1 metformin, 4 liraglutide, 5 oxytocin, 1 naltrexone-bupropion). All studies reported improved hyperphagia with variable BMI effects. Ten adolescents met case series eligibility (mean age 13.2 ± 2.6 years, 40% female; AOMs: 6 metformin, 5 topiramate, 2 semaglutide, 3 liraglutide). After AOM course, 60% had decreased or stable BMI z-score. No significant side effects. (4) Conclusions: results suggest AOMs may be useful for weight management in youth with PWS. Additional studies are required to validate findings and support AOM treatment guidelines.

Effectiveness of Combining Antiobesity Medication With an Employer-Based Weight Management Program for Treatment of Obesity: A Randomized Clinical Trial

IMPORTANCE

The clinical efficacy of antiobesity medications (AOMs) as adjuncts to lifestyle intervention is well characterized, but data regarding their use in conjunction with workplace wellness plans are lacking, and coverage of AOMs by US private employers is limited.

OBJECTIVE

To determine the effect of combining AOMs with a comprehensive, interdisciplinary, employer-based weight management program (WMP) compared with the WMP alone on weight loss, treatment adherence, and work productivity and limitations.

DESIGN, SETTING, AND PARTICIPANTS

This 1-year, single-center, open-label, parallel-group, real-world, randomized clinical trial was conducted at the Cleveland Clinic's Endocrinology and Metabolism Institute in Cleveland, Ohio, from January 7, 2019, to May 22, 2020. Participants were adults with obesity (body mass index [BMI; calculated as weight in kilograms divided by height in meters squared] ≥30) enrolled in the Cleveland Clinic Employee Health Plan.

INTERVENTIONS

In total, 200 participants were randomized 1:1, 100 participants to WMP combined with an AOM (WMP+Rx), and 100 participants to WMP alone. The WMP was the Cleveland Clinic Endocrinology and Metabolism Institute's employer-based integrated medical WMP implemented through monthly multidisciplinary shared medical appointments. Participants in the WMP+Rx group initiated treatment with 1 of 5 US Food and Drug Administration-approved medications for chronic weight management (orlistat, lorcaserin, phentermine/topiramate, naltrexone/bupropion, and liraglutide, 3.0 mg) according to standard clinical practice.

MAIN OUTCOMES AND MEASURES

The primary end point was the percentage change in body weight from baseline to month 12.

RESULTS

The 200 participants were predominately (177 of 200 [88.5%]) women, had a mean (SD) age of 50.0 (10.3) years, and a mean (SD) baseline weight of 105.0 (19.0) kg. For the primary intention-to-treat estimand, the estimated mean (SE) weight loss was -7.7% (0.7%) for the WMP+Rx group vs -4.2% (0.7%) for the WMP group, with an estimated treatment difference of -3.5% (95% CI, -5.5% to -1.5%) (P < .001). The estimated percentage of participants achieving at least 5% weight loss was 62.5% for WMP+Rx vs 44.8% for WMP (P = .02). The rate of attendance at shared medical appointments was higher for the WMP+Rx group than for the WMP group. No meaningful differences in patient-reported work productivity or limitation measures were observed.

CONCLUSIONS AND RELEVANCE

Clinically meaningful superior mean weight loss was achieved when access to AOMs was provided in the real-world setting of an employer-based WMP, compared with the WMP alone. Such results may inform employer decisions regarding AOM coverage and guide best practices for comprehensive, interdisciplinary employer-based WMPs.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03799198.

Probing the Release of Bupropion and Naltrexone Hydrochloride Salts from Biopolymeric Matrices of Diverse Chemical Structures

In the last decades, the notion of including excipients in the formulations, as inert substances aiding production processes, has changed and they are recently viewed as multifunctional discrete entities. It is now well documented that excipients serve several roles, spreading from the stabilization and modified release, to providing biocompatible properties and targeting moieties. The aim of this study was to develop matrix-based oral drug delivery systems of bupropion hydrochloride (BUP·HCl) and naltrexone hydrochloride (NTX·HCl), suitable for releasing these active substances in a modified manner, providing a stable level of drug release, which is simultaneously therapeutically effective and non-toxic, thus reducing side effects, after a single dose administration, throughout the gastrointestinal tract. The new formulations, employing hydroxypropylmethycellulose (HPMC K15M) (a cellulosic polymer, which, generally hydrates to form a gelatinous layer that is critical to prevent wetting and rapid drug release from the matrices), poly(methacylic acid-co-ethyl acrylate) 1:1 (Eudragit^® L100-55: effective for site specific drug delivery in intestine), poly(ethylene oxide) (PEO) (7 × 10⁶: a high molecular weight polymer, water-soluble, in micro-granular powder form), as the rate controlling polymers, were chosen to lead to a "soothing out" release pattern of these drugs, at 0 ≤ t ≤ 120 min. Moreover, the release of the two drugs from the ulvan-based tablets, was found to follow the desired profile, throughout the entire course of the dissolution experiments.

An open-label trial on the efficacy and tolerability of naltrexone/bupropion SR for treating altered eating behaviours and weight loss in binge eating disorder

PURPOSE

Binge eating disorder (BED) has a considerable clinical relevance by virtue of its high numerous psychiatric and medical comorbidities; among the latter, the most frequent is obesity. Available treatments for BED have shown frequent relapse of binges or weight regain in the long term. The new combination of naltrexone and bupropion sustained release (NB) has proved to be effective for weight loss among obese patients. As NB acts on hypothalamic and reward circuits, that seem involved in the pathogenesis and maintenance of BED symptoms, this study aims to evaluate the efficacy of NB in improving pathological eating behavior and losing weight in BED patients.

METHODS

In this preliminary study, 23 obese-BED patients and a control group of 20 obese non-BED patients (respectively, Groups 1 and 2) who had previously undergone at least 5 unsuccessful weight-loss programs were treated with NB in addition to modified life style. Evaluation at t0 and after 16 weeks of treatment (t1) included anthropometric measurement, eating behavior assessment and psychopathological questionnaires (EDE-Q, BES, YFAS, BDI and STAI).

RESULTS

A significant and similar weight loss (ΔBMI% ≈ 8%) was evident for both groups. Pathological eating behavior (i.e., binge, grazing, emotional eating, craving for carbohydrates, and post-dinner eating), BES score and YFAS severity significantly improved, especially among BED. NB was well tolerated and drop-out rate was low.

CONCLUSION

Treatment with NB, in addition to a reduced-calorie diet and increased physical activity, seems an effective and well-tolerated option for improving pathological eating behavior and losing weight in obese-BED patients.

LEVEL OF EVIDENCE

Level III case-control study.

A Practical Approach to Assist Asthmatics to Lose Weight

Treating patients with obesity, particularly asthmatics, is a complex challenge that requires a unique and individually tailored approach. Obesity, defined by the Centers for Disease Control and Prevention, is a body mass index of 30.0 kg/m² or greater. It affects approximately 43% of adults and 19% of youth in America. It is a multifactorial disease and should be managed with the same intensity as any other medical problem, for it represents a risk factor for the onset and severity of asthma. Furthermore, it is a comorbid condition that exacerbates rhinosinusitis, gastroesophageal reflux disease, obstructive sleep apnea, hypertension, anxiety, and depression. Being obese also increases morbidity for cardio/cerebrovascular diseases, metabolic syndrome, type 2 diabetes, breast and bladder cancer, and migraines. Osteoarthritis, in particular, of the knees and hips, is also associated with obesity, and that too will complicate asthma by hindering a subject's mobility and ability to exercise. This paper reviews the epidemiology and pathophysiology of obesity, its effect on asthma, and practical strategies to achieve weight loss.

The Neurobiology of Binge-eating Disorder Compared with Obesity: Implications for Differential Therapeutics

PURPOSE

Emerging work indicates divergence in the neurobiologies of binge-eating disorder (BED) and obesity despite their frequent co-occurrence. This review highlights specific distinguishing aspects of BED, including elevated impulsivity and compulsivity possibly involving the mesocorticolimbic dopamine system, and discusses implications for differential therapeutics for BED.

METHODS

This narrative review describes epidemiologic, clinical, genetic, and preclinical differences between BED and obesity. Subsequently, this review discusses human neuroimaging work reporting differences in executive functioning, reward processing, and emotion reactivity in BED compared with obesity. Finally, on the basis of the neurobiology of BED, this review identifies existing and new therapeutic agents that may be most promising given their specific targets based on putative mechanisms of action relevant specifically to BED.

FINDINGS

BED is characterized by elevated impulsivity and compulsivity compared with obesity, which is reflected in divergent neurobiological characteristics and effective pharmacotherapies. Therapeutic agents that influence both reward and executive function systems may be especially effective for BED.

IMPLICATIONS

Greater attention to impulsivity/compulsivity-related, reward-related, and emotion reactivity-related processes may enhance conceptualization and treatment approaches for patients with BED. Consideration of these distinguishing characteristics and processes could have implications for more targeted pharmacologic treatment research and interventions.

Interventions for the management of obesity in people with bipolar disorder

BACKGROUND

Bipolar disorder is one of the most common serious mental illnesses, affecting approximately 60 million people worldwide. Characterised by extreme alterations in mood, cognition, and behaviour, bipolar disorder can have a significant negative impact on the functioning and quality of life of the affected individual. Compared with the general population, the prevalence of comorbid obesity is significantly higher in bipolar disorder. Approximately 68% of treatment seeking bipolar patients are overweight or obese. Clinicians are aware that obesity has the potential to contribute to other physical health conditions in people with bipolar disorder, including diabetes, hypertension, metabolic syndrome, cardiovascular disease, and coronary heart disease. Cardiovascular disease is the leading cause of premature death in bipolar disorder, happening a decade or more earlier than in the general population. Contributing factors include illness-related factors (mood-related factors, i.e. mania or depression), treatment-related factors (weight implications and other side effects of medications), and lifestyle factors (physical inactivity, poor diet, smoking, substance abuse). Approaches to the management of obesity in individuals with bipolar disorder are diverse and include non-pharmacological interventions (i.e. dietary, exercise, behavioural, or multi-component), pharmacological interventions (i.e. weight loss drugs or medication switching), and bariatric surgery.

OBJECTIVES

To assess the effectiveness of interventions for the management of obesity in people with bipolar disorder.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trials Register (CCMDCTR) and the Cochrane Central Register for Controlled Trials (CENTRAL) to February 2019. We ran additional searches via Ovid databases including MEDLINE, Embase, and PsycInfo to May 2020. We searched the World Health Organization (WHO) trials portal (International Clinical Trials Registry Platform (ICTRP)) and ClinicalTrials.gov. We also checked the reference lists of all papers brought to full-text stage and all relevant systematic reviews.

SELECTION CRITERIA

Randomised controlled trials (RCTs), randomised at the level of the individual or cluster, and cross-over designs of interventions for management of obesity, in which at least 80% of study participants had a clinical diagnosis of bipolar disorder and comorbid obesity (body mass index (BMI) ≥ 30 kg/m²), were eligible for inclusion. No exclusions were based on type of bipolar disorder, stage of illness, age, or gender. We included non-pharmacological interventions comprising dietary, exercise, behavioural, and multi-component interventions; pharmacological interventions consisting of weight loss medications and medication switching interventions; and surgical interventions such as gastric bypass, gastric bands, biliopancreatic diversion, and vertical banded gastroplasty. Comparators included the following approaches: dietary intervention versus inactive comparator; exercise intervention versus inactive comparator; behavioural intervention versus inactive comparator; multi-component lifestyle intervention versus inactive comparator; medication switching intervention versus inactive comparator; weight loss medication intervention versus inactive comparator; and surgical intervention versus inactive comparator. Primary outcomes of interest were changes in body mass, patient-reported adverse events, and quality of life.

DATA COLLECTION AND ANALYSIS

Four review authors were involved in the process of selecting studies. Two review authors independently screened the titles and abstracts of studies identified in the search. Studies brought to the full-text stage were then screened by another two review authors working independently. However, none of the full-text studies met the inclusion criteria. Had we included studies, we would have assessed their methodological quality by using the criteria recommended in the Cochrane Handbook for Systematic Reviews of Interventions. We intended to combine dichotomous data using risk ratios (RRs), and continuous data using mean differences (MDs). For each outcome, we intended to calculate overall effect size with 95% confidence intervals (CIs).

MAIN RESULTS

None of the studies that were screened met the inclusion criteria.

AUTHORS' CONCLUSIONS

None of the studies that were assessed met the inclusion criteria of this review. Therefore we were unable to determine the effectiveness of interventions for the management of obesity in individuals with bipolar disorder. Given the extent and impact of the problem and the absence of evidence, this review highlights the need for research in this area. We suggest the need for RCTs that will focus only on populations with bipolar disorder and comorbid obesity. We identified several ongoing studies that may be included in the update of this review.

Obesity Treatment: A Focus on Pharmacotherapy of Weight Management

Obesity, a chronic multifactorial disease, has been on the rise in the United States in recent years. It paves a way to other chronic conditions and related morbidity and mortality. The treatment of obesity should have a chronic approach involving lifestyle modifications from the very beginning. Along with reduced calorie diet, increased physical activity, and behavior modifications, various short- and long-term pharmacological agents are available to help with the weight loss. For qualifying patients, selection of an appropriate agent based on its mechanism, efficacy, and safety profile as well as patient preference can provide desired outcomes. This medical weight management should be a multidisciplinary approach involving nurses to provide continuous patient education and motivation.

The Opioid System and Food Intake: Use of Opiate Antagonists in Treatment of Binge Eating Disorder and Abnormal Eating Behavior

Eating disorders (EDs) and substance use disorders (SUDs) commonly co-occur, especially in conjunction with affective syndromes, yet little is known about opiate abuse and ED symptoms in patients on naltrexone-bupropion therapy. Moreover, evidence suggests that the opioid system can also be regarded as one of the major systems regulating the anticipatory processes preceding binge eating episodes. The lack of evidence in the effectiveness of psychotherapy treatment in addition to psychotropic mediations compounds the difficulties in stabilizing individuals with EDs. This article aims to exhaustively review literature relating to the use of opioid antagonists in the management of binge eating disorder (BED) and other abnormal eating habits and how this can be augmented by the use of psychological approaches to come up with the most effective therapy or combination of therapies to manage these conditions. Although this approach is promising, it has not been evaluated. A review of the literature pertaining to the use of naltrexone in patients with EDs was performed through PubMed, PsycINFO and MEDLINE. We selected 63 relevant articles published between 1981 and 2018 and those written in English. Search terms included “Opioid antagonists”, “naltrexone”, “bupropion” and “Psychotherapy” each combined with “Binge Eating Disorder”, “Bulimia Nervosa”, “Anorexia Nervosa”, “Eating Disorder”, “EDNOS” and “Obesity”. While working with these articles, we also identified several problems related to use of these methods in real clinical practice. Seventy-seven articles were reviewed, and 63 were selected for inclusion. Data obtained from these sources confirmed that the blockade of opioid receptors diminishes food intake. More recent findings also indicate that the combination of bupropion and naltrexone can induce weight loss. Augmentation of this by introducing psychotherapy may lead to better outcomes. Cognitive behavioral therapy (CBT) was the most frequently recommended psychotherapy intervention, showing efficacy for EDs and chemical addictions as documented by most of the studies, but with uncertain efficacy when utilized as augmentation strategy. There are limited data supporting the use of psychotherapy in augmentation of standard therapy in ED; however, there is evidence to support that psychotherapy is safe in this population and has been effective in cases of patients with opiate addiction with and without psychiatric comorbidities as well as BED. More research is needed to establish treatment guidelines. Combining pharmacotherapeutic and psychotherapeutic interventions leads to the achievement of a better outcome in managing patients with EDs. Involving families or the use of support groups increases chances of adherence to the prescribed interventions resulting in higher rates of remission. However, it is clear that all of these interventions must occur in the context of a comprehensive treatment program. We believe that patient-specific psychotherapy may not only facilitate the treatment process, but also cause significant alterations in eating pattern. This approach for BED may lead to more significant treatment outcomes, but this possibility must be tested in larger samples.

Safety and Efficacy of Weight-Loss Pharmacotherapy in Persons Living with HIV: A Review of the Literature and Potential Drug-Drug Interactions with Antiretroviral Therapy

The prevalence of obesity among persons living with human immunodeficiency virus (HIV) has increased significantly and may be linked to the use of antiretroviral therapy. Although weight-loss medications approved by the U.S. Food and Drug Administration are recommended as an adjunct to diet and exercise to treat obesity in the general population, little is known about the safety and efficacy of these drugs specifically in persons living with HIV. We review the available evidence regarding the effective use of weight-loss pharmacotherapy in persons living with HIV and its potential to interact with antiretroviral therapy. Persons living with HIV are frequently not reported or included in clinical trials for weight-loss medications; however, treatment efficacy is likely similar to the general population. Several important reported or theoretical drug-drug interactions exist between antiobesity pharmacotherapy and antiretroviral therapy. Orlistat is a weight-loss drug available in the United States without a prescription and was linked to HIV viral rebound in several case reports. Clinicians should be aware of the potential for loss of HIV viremia control when certain weight-loss pharmacotherapies are used in combination with antiretrovirals.

Cardiovascular Risks and Benefits of Medications Used for Weight Loss

Obesity is a complex disease influenced by many neurohormonal pathways which regulate body weight toward homeostasis. Presently, the disease of obesity effects over a billion individuals worldwide with scalable treatment options in dire need. Pharmacologic interventions for obesity have been developed to help promote weight loss in individuals with obesity. This area is rapidly developing and will only exponentially increase to serve the demand for persons with obesity seeking biologically orientated solutions to treat their disease. Therefore, understanding the cardiovascular risks and benefits of these weight loss medications is of particularly importance due to obesities strong association with cardiovascular (CV) disease risk. Moreover, past experiences with pharmacotherapy agents with weight loss properties have demonstrated an association with adverse CV outcomes, leading to market removal, in most cases and concerns over using similar medications. To better understand the CV risks and benefits pharmacotherapy agents used for weight loss, this review will discuss medications which are FDA-approved for weight loss, as well as medications commonly used off-label for this indication. The goal is to provide an overview of the risks and benefits many of these medications can offer to help guide clinical decision making and patient education.

Cardiovascular risk and obesity

BACKGROUND

This is an overview of the mechanisms of obesity and its relation to cardiovascular risks, describing the available treatment options to manage this condition.

MAIN BODY

The pathogenesis of obesity includes the balance between calories consumed and energy expenditure followed by the maintenance of body weight. Diet, physical activity, environmental, behavioral and physiological factors are part of the complex process of weight loss, since there are several hormones and peptides involved in regulation of appetite, eating behavior and energy expenditure. The cardiovascular complications associated to obesity are also driven by processes involving hormones and peptides and which include inflammation, insulin resistance, endothelial dysfunction, coronary calcification, activation of coagulation, renin angiotensin or the sympathetic nervous systems. Pharmacological treatments are often needed to insure weight loss and weight maintenance as adjuncts to diet and physical activity in people with obesity and overweight patients.

CONCLUSION

To accomplish satisfactory goals, patients and physicians seek for weight loss, weight maintenance and improvement of the risk factors associated to this condition, especially cardiovascular risk.

Cardiovascular Risks and Benefits of Medications Used for Weight Loss

Obesity is a complex disease influenced by many neurohormonal pathways which regulate body weight toward homeostasis. Presently, the disease of obesity effects over a billion individuals worldwide with scalable treatment options in dire need. Pharmacologic interventions for obesity have been developed to help promote weight loss in individuals with obesity. This area is rapidly developing and will only exponentially increase to serve the demand for persons with obesity seeking biologically orientated solutions to treat their disease. Therefore, understanding the cardiovascular risks and benefits of these weight loss medications is of particularly importance due to obesities strong association with cardiovascular (CV) disease risk. Moreover, past experiences with pharmacotherapy agents with weight loss properties have demonstrated an association with adverse CV outcomes, leading to market removal, in most cases and concerns over using similar medications. To better understand the CV risks and benefits pharmacotherapy agents used for weight loss, this review will discuss medications which are FDA-approved for weight loss, as well as medications commonly used off-label for this indication. The goal is to provide an overview of the risks and benefits many of these medications can offer to help guide clinical decision making and patient education.

Pharmacological interventions for obesity: current and future targets

PURPOSE OF REVIEW

Obesity in the United States has been on a constant rise since the Center for Disease Control and Prevention (CDC) began tracking it over 50 years ago. Despite focused attention on this epidemic, pharmacological treatments aimed at obesity are lacking. Here, we briefly give perspective on the central and peripheral mechanisms underlying feeding behaviors and describe the existing pharmacological treatments for obesity. With this lens, I suggest future targets for the treatment of obesity.

RECENT FINDINGS

Given the development of genetic and molecular tools, understanding of how energy expenditure is modulated is becoming more nuanced. There is growing evidence for a link between obesity and addiction, which should be utilized in the development of new pharmacological treatments.

SUMMARY

More focus is needed on identifying targets for anti-obesity pharmacology. In doing so, research should include intensive investigation of the brain's reward circuitry.

Obesity management in Prader-Willi syndrome: current perspectives

Prader-Willi syndrome (PWS) is a complex multisystem disorder due to the absent expression of the paternally active genes in the PWS critical region on chromosome 15 (15q11.2-q13). The syndrome is considered the most common genetic cause of obesity, occurring in 1:10,000-1:30,000 live births. Its main characteristics include neonatal hypotonia, poor feeding, and lack of appetite in infancy, followed by weight gain, lack of satiety, and uncontrolled appetite, frequently after the age of 2-3 years. The clinical picture includes short stature, multiple endocrine abnormalities (hypogonadism, growth hormone/insulin-like growth factor-I axis dysfunction, hypothyroidism, central adrenal insufficiency), dysmorphic features, scoliosis, osteoporosis, mental retardation, and behavioral and psychiatric problems. Subjects with PWS will become severely obese unless their food intake is strictly controlled. Constant and obsessive food seeking behavior can make life very difficult for both the family and caretakers. Prevention of obesity is mandatory in these patients from the first years of life, because once obesity develops it is difficult to maintain the control of food intake. In fact, PWS subjects die prematurely from complications conventionally related to obesity, including diabetes mellitus, metabolic syndrome, sleep apnea, respiratory insufficiency, and cardiovascular disease. The mechanisms underlying hyperphagia in PWS are not completely known, and to date no drugs have proven their efficacy in controlling appetite. Consequently, dietary restriction, physical activity, and behavior management are fundamental in the prevention and management of obesity in PWS. In spite of all available therapeutic tools, however, successful weight loss and maintenance are hardly accomplished. In this context, clinical trials with new drugs have been initiated in order to find new possibilities of a therapy for obesity in these patients. The preliminary results of these studies seem to be encouraging. On the other hand, until well-proven medical treatments are available, bariatric surgery can be taken into consideration, especially in PWS patients with life-threatening comorbidities.

Combination therapy for obesity

Obesity is a chronic disease with serious consequences and although lifestyle modification is considered first line treatment, it is often ineffective, especially in the long term. Relatively few people with obesity will undergo the most effective currently available treatment of bariatric surgery. Pharmacotherapy can bridge the gap between lifestyle modification and surgery, but many monotherapies have only modest efficacy or require high doses with unacceptable side effects. As with many other areas of medicine, combination therapy is now becoming accepted as a way of optimising efficacy for weight management, whilst minimising adverse effects. Combinations may use different medications with complementary modes of action. Currently available combination therapies are low-dose phentermine and sustained release topiramate and naltrexone/bupropion. Many other possibilities exist and promising options include combination of phentermine with a sodium glucose co-transporter 2 inhibitor or combination of a glucagon-like peptide 1 agonist with other gut hormones or with a sodium glucose co-transporter 2 inhibitor. The ultimate aim is to match the efficacy of bariatric surgery with a combination of medicines, but this remains an elusive goal.

Pharmacotherapy for Weight Management in the VHA

Weight management medications (WMM) are underutilized as an adjunct to behavioral and lifestyle interventions. In fiscal years 2014-2015, a total of approximately 2500 veterans-a mere 2% of veterans receiving care from the Veterans Health Administration (VHA)-eligible for a WMM received a prescription for one. A State of the Art Conference on Weight Management workgroup, focused on pharmacotherapy, developed evidence-based recommendations and strategies to foster the appropriate use of WMM in the VHA. The workgroup identified patient, prescriber, and health system barriers to and facilitators for prescribing WMM. Barriers included patient and provider concerns about medication safety and efficacy, limited involvement of primary care, restrictive medication criteria for use (CFU), and skepticism among providers regarding the safety and efficacy of WMM and the perception of obesity as a disease. Potential facilitators for removing barriers included patient and provider education about WMM and the health benefits of weight loss, increased engagement of primary care providers in weight management, relaxation of the CFU, and creation of a system to help patients navigate through weight management treatment options. Several research questions were framed with regard to WMM in general, and specifically to the care of obese veterans. While some of the workgroup's conclusions reflect issues specific to the VHA, many are likely to be applicable to other health organizations.

Pediatric Obesity-Assessment, Treatment, and Prevention: An Endocrine Society Clinical Practice Guideline

COSPONSORING ASSOCIATIONS

The European Society of Endocrinology and the Pediatric Endocrine Society. This guideline was funded by the Endocrine Society.

OBJECTIVE

To formulate clinical practice guidelines for the assessment, treatment, and prevention of pediatric obesity.

PARTICIPANTS

The participants include an Endocrine Society-appointed Task Force of 6 experts, a methodologist, and a medical writer.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The Task Force commissioned 2 systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Endocrine Society committees and members and co-sponsoring organizations reviewed and commented on preliminary drafts of this guideline.

CONCLUSION

Pediatric obesity remains an ongoing serious international health concern affecting ∼17% of US children and adolescents, threatening their adult health and longevity. Pediatric obesity has its basis in genetic susceptibilities influenced by a permissive environment starting in utero and extending through childhood and adolescence. Endocrine etiologies for obesity are rare and usually are accompanied by attenuated growth patterns. Pediatric comorbidities are common and long-term health complications often result; screening for comorbidities of obesity should be applied in a hierarchal, logical manner for early identification before more serious complications result. Genetic screening for rare syndromes is indicated only in the presence of specific historical or physical features. The psychological toll of pediatric obesity on the individual and family necessitates screening for mental health issues and counseling as indicated. The prevention of pediatric obesity by promoting healthful diet, activity, and environment should be a primary goal, as achieving effective, long-lasting results with lifestyle modification once obesity occurs is difficult. Although some behavioral and pharmacotherapy studies report modest success, additional research into accessible and effective methods for preventing and treating pediatric obesity is needed. The use of weight loss medications during childhood and adolescence should be restricted to clinical trials. Increasing evidence demonstrates the effectiveness of bariatric surgery in the most seriously affected mature teenagers who have failed lifestyle modification, but the use of surgery requires experienced teams with resources for long-term follow-up. Adolescents undergoing lifestyle therapy, medication regimens, or bariatric surgery for obesity will need cohesive planning to help them effectively transition to adult care, with continued necessary monitoring, support, and intervention. Transition programs for obesity are an uncharted area requiring further research for efficacy. Despite a significant increase in research on pediatric obesity since the initial publication of these guidelines 8 years ago, further study is needed of the genetic and biological factors that increase the risk of weight gain and influence the response to therapeutic interventions. Also needed are more studies to better understand the genetic and biological factors that cause an obese individual to manifest one comorbidity vs another or to be free of comorbidities. Furthermore, continued investigation into the most effective methods of preventing and treating obesity and into methods for changing environmental and economic factors that will lead to worldwide cultural changes in diet and activity should be priorities. Particular attention to determining ways to effect systemic changes in food environments and total daily mobility, as well as methods for sustaining healthy body mass index changes, is of importance.

Natural Products with Anti-obesity Effects and Different Mechanisms of Action

Obesity, a primary influence on health condition, causes numerous comorbidities and complications and, therefore, pharmacotherapy is considered a strategy for its treatment. However, the adverse effects of most chemical drugs targeting weight loss complicate their approval by regulatory authorities. Recently, interest has increased in the development of ingredients from natural sources with fewer adverse effects for preventing and ameliorating obesity. This review provides an overview of current anti-obesity drugs and natural products with anti-obesity properties as well as their mechanisms of action, which include interfering with nutrient absorption, decreasing adipogenesis, increasing energy expenditure (thermogenesis), appetite suppression, modifying intestinal microbiota composition, and increasing fecal fat excretion.

Management of Obesity

This review examines weight loss and accompanying improvements in obesity-related comorbidities produced by intensive lifestyle intervention, pharmacotherapy, and bariatric surgery. Obese individuals lose approximately 6 to 8 kg (approximately 6% to 8% of initial weight) with 6 months of participation in a high-intensity lifestyle intervention (≥ 14 treatment visits) consisting of diet, physical activity, and behavior therapy. Such losses reduce progression to type 2 diabetes in at-risk people and decrease blood pressure and triglyceride levels. All diets, regardless of macronutrient composition, can produce clinically meaningful weight loss (> 5%) if they induce a deficit ≥ 500 kcal/d. Physical activity of 150 to 180 min/wk yields modest short-term weight loss compared with diet but contributes to improvements in obesity-related conditions. Gradual weight regain is common after lifestyle intervention but can be prevented by continued participation in monthly weight loss maintenance sessions, as well as by high levels of physical activity (ie, 200 to 300 min/wk). Patients unable to reduce satisfactorily with lifestyle intervention may be candidates for pharmacotherapy, recommended as an adjunct. Five medications have been approved by the US Food and Drug Administration for chronic weight management, and each has its own risk/benefit profile. The addition of these medications to lifestyle intervention increases mean weight loss by 2.5 to 8.9 kg compared with placebo. Patients with severe obesity who are unable to reduce successfully with lifestyle intervention and pharmacotherapy are eligible for bariatric surgery, including Roux-en-Y gastric bypass, sleeve gastrectomy, or adjustable gastric banding. The first two procedures yield long-term (≥ 3 years) reductions of ≥ 20% of initial weight that are associated with decreases in morbidity and potentially mortality. Greater resources and dissemination efforts are needed to increase the availability of these three approaches for the millions of Americans who would benefit from them.

Hypothalamic kappa opioid receptor mediates both diet-induced and melanin concentrating hormone-induced liver damage through inflammation and endoplasmic reticulum stress

The opioid system is widely known to modulate the brain reward system and thus affect the behavior of humans and other animals, including feeding. We hypothesized that the hypothalamic opioid system might also control energy metabolism in peripheral tissues. Mice lacking the kappa opioid receptor (κOR) and adenoviral vectors overexpressing or silencing κOR were stereotaxically delivered in the lateral hypothalamic area (LHA) of rats. Vagal denervation was performed to assess its effect on liver metabolism. Endoplasmic reticulum (ER) stress was inhibited by pharmacological (tauroursodeoxycholic acid) and genetic (overexpression of the chaperone glucose-regulated protein 78 kDa) approaches. The peripheral effects on lipid metabolism were assessed by histological techniques and western blot. We show that in the LHA κOR directly controls hepatic lipid metabolism through the parasympathetic nervous system, independent of changes in food intake and body weight. κOR colocalizes with melanin concentrating hormone receptor 1 (MCH-R1) in the LHA, and genetic disruption of κOR reduced melanin concentrating hormone-induced liver steatosis. The functional relevance of these findings was given by the fact that silencing of κOR in the LHA attenuated both methionine choline-deficient, diet-induced and choline-deficient, high-fat diet-induced ER stress, inflammation, steatohepatitis, and fibrosis, whereas overexpression of κOR in this area promoted liver steatosis. Overexpression of glucose-regulated protein 78 kDa in the liver abolished hypothalamic κOR-induced steatosis by reducing hepatic ER stress.

CONCLUSIONS

This study reveals a novel hypothalamic-parasympathetic circuit modulating hepatic function through inflammation and ER stress independent of changes in food intake or body weight; these findings might have implications for the clinical use of opioid receptor antagonists. (Hepatology 2016;64:1086-1104).

The interface of depression and obesity

Depression and obesity are both highly prevalent and are leading public health problems. These foregoing disorders independently have great impact on morbidity and mortality affecting patients' health and well-being as well as on the socioeconomic aspect of functional impairment and healthcare expenditure. Results from epidemiological studies, clinical trials and recent meta-analyses support the association between mood disorders and obesity as both frequently co-occur in all races of populations examined. It is now well-established through longitudinal studies that obesity is a risk factor for mood disorders and vice versa. In the current review, we aim to address the evidence regarding 4 questions: (1) does obesity moderate response to antidepressants among patients with depressive disorders?, (2) does the presence of depressive disorders moderate the progression or outcome of obesity?, (3) does treatment of obesity moderate outcomes among patients with depressive disorders?, and (4) does treatment of depressive disorders moderate outcomes of obesity? In order to improve the interpretability of the results we confined the evaluations to studies where patients met the criteria for depressive disorders or obesity (i.e. BMI>30). Extant evidence supports the association between obesity and adverse health outcomes among individuals with depressive disorders. In addition, the treatment of one condition (i.e. obesity or depressive disorders) appears to improve the course of the other condition. It might be beneficial to check for the other condition in patients presenting with one condition and treatment should be administered to treat both conditions.

Chiral Plasma Pharmacokinetics and Urinary Excretion of Bupropion and Metabolites in Healthy Volunteers

Bupropion, widely used as an antidepressant and smoking cessation aid, undergoes complex metabolism to yield numerous metabolites with unique disposition, effect, and drug-drug interactions (DDIs) in humans. The stereoselective plasma and urinary pharmacokinetics of bupropion and its metabolites were evaluated to understand their potential contributions to bupropion effects. Healthy human volunteers (n = 15) were administered a single oral dose of racemic bupropion (100 mg), which was followed by collection of plasma and urine samples and determination of bupropion and metabolite concentrations using novel liquid chromatography-tandem mass spectrometry assays. Time-dependent, elimination rate-limited, stereoselective pharmacokinetics were observed for all bupropion metabolites. Area under the plasma concentration-time curve from zero to infinity ratios were on average approximately 65, 6, 6, and 4 and Cmax ratios were approximately 35, 6, 3, and 0.5 for (2R,3R)-/(2S,3S)-hydroxybupropion, R-/S-bupropion, (1S,2R)-/(1R,2S)-erythrohydrobupropion, and (1R,2R)-/(1S,2S)-threohydrobupropion, respectively. The R-/S-bupropion and (1R,2R)-/(1S,2S)-threohydrobupropion ratios are likely indicative of higher presystemic metabolism of S- versus R-bupropion by carbonyl reductases. Interestingly, the apparent renal clearance of (2S,3S)-hydroxybupropion was almost 10-fold higher than that of (2R,3R)-hydroxybupropion. The prediction of steady-state pharmacokinetics demonstrated differential stereospecific accumulation [partial area under the plasma concentration-time curve after the final simulated bupropion dose (300-312 hours) from 185 to 37,447 nM⋅h] and elimination [terminal half-life of approximately 7-46 hours] of bupropion metabolites, which may explain observed stereoselective differences in bupropion effect and DDI risk with CYP2D6 at steady state. Further elucidation of bupropion and metabolite disposition suggests that bupropion is not a reliable in vivo marker of CYP2B6 activity. In summary, to our knowledge, this is the first comprehensive report to provide novel insight into mechanisms underlying bupropion disposition by detailing the stereoselective pharmacokinetics of individual bupropion metabolites, which will enhance clinical understanding of bupropion's effects and DDIs with CYP2D6.

Topiramate monotherapy for weight reduction in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

AIMS

To conduct a systematic review with meta-analysis to determine the efficacy and safety of topiramate as monotherapy for weight reduction in patients with type 2 diabetes mellitus.

METHODS

We searched MEDLINE, Embase, and International Pharmaceutical Abstracts from inception to June 2015. We included randomized controlled trials that evaluated topiramate monotherapy versus control agents or placebo for weight loss in obese type 2 diabetes patients.

RESULTS

Of the 284 studies identified, 5 studies fulfilled the inclusion criteria. Topiramate decreased weight by a mean difference of 3.4kg (95% CI, -3.79 to -3.04) compared to placebo. Mean HbA1c reduction of -0.4% (95% CI, -0.58 to -0.32) and mean BMI reduction of -1.43kg/m(2) (95% CI, -1.83 to -1.03) were both significantly observed with topiramate (p<0.00001). Serious and total adverse events occurred more commonly among topiramate users, with a risk ratio for serious adverse events of 1.69 (95% CI, 1.00-2.87). All but one study had high risk of bias.

CONCLUSIONS

Topiramate monotherapy reduced weight in obese type 2 diabetes patients, but increased adverse events including serious adverse events. Given these safety concerns and the absence of data on clinically meaningful efficacy endpoints, clinicians should generally avoid use of topiramate alone for this indication.

Naltrexone/bupropion for the treatment of obesity and obesity with Type 2 diabetes

Contrave® is a combination of naltrexone hydrochloride extended release and bupropion hydrochloride extended release for the treatment of obesity, and is used with lifestyle modification. Its safety and efficacy were assessed in four randomized, double-blind, placebo-controlled, 56-week Phase III clinical trials in 4536 adult subjects: COR-1, COR-II, COR-BMOD and COR-DM. All four studies demonstrated statistically significant and clinically meaningful weight loss following up to 52 weeks of treatment with naltrexone/bupropion compared with placebo. The average weight loss from baseline across the four studies was approximately 11–22 lbs (5–9 kg). Results show the efficacy of Contrave for weight loss, as well as significant improvements in cardiometabolic markers. This review focuses on the four studies, their outcomes and the mechanism of action of Contrave.

Stereoselective Glucuronidation of Bupropion Metabolites In Vitro and In Vivo

Bupropion is a widely used antidepressant and smoking cessation aid in addition to being one of two US Food and Drug Administration-recommended probe substrates for evaluation of cytochrome P450 2B6 activity. Racemic bupropion undergoes oxidative and reductive metabolism, producing a complex profile of pharmacologically active metabolites with relatively little known about the mechanisms underlying their elimination. A liquid chromatography-tandem mass spectrometry assay was developed to simultaneously separate and detect glucuronide metabolites of (R,R)- and (S,S)-hydroxybupropion, (R,R)- and (S,S)-hydrobupropion (threo) and (S,R)- and (R,S)-hydrobupropion (erythro), in human urine and liver subcellular fractions to begin exploring mechanisms underlying enantioselective metabolism and elimination of bupropion metabolites. Human liver microsomal data revealed marked glucuronidation stereoselectivity [Cl(int), 11.4 versus 4.3 µl/min per milligram for the formation of (R,R)- and (S,S)-hydroxybupropion glucuronide; and Cl(max), 7.7 versus 1.1 µl/min per milligram for the formation of (R,R)- and (S,S)-hydrobupropion glucuronide], in concurrence with observed enantioselective urinary elimination of bupropion glucuronide conjugates. Approximately 10% of the administered bupropion dose was recovered in the urine as metabolites with glucuronide metabolites, accounting for approximately 40%, 15%, and 7% of the total excreted hydroxybupropion, erythro-hydrobupropion, and threo-hydrobupropion, respectively. Elimination pathways were further characterized using an expressed UDP-glucuronosyl transferase (UGT) panel with bupropion enantiomers (both individual and racemic) as substrates. UGT2B7 catalyzed the stereoselective formation of glucuronides of hydroxybupropion, (S,S)-hydrobupropion, (S,R)- and (R,S)-hydrobupropion; UGT1A9 catalyzed the formation of (R,R)-hydrobupropion glucuronide. These data systematically describe the metabolic pathways underlying bupropion metabolite disposition and significantly expand our knowledge of potential contributors to the interindividual and intraindividual variability in therapeutic and toxic effects of bupropion in humans.

Gastrointestinal traits: individualizing therapy for obesity with drugs and devices

BACKGROUND AND AIMS

The aims of this article were to review the discrepancy between numbers of people requiring weight loss treatment and results and to assess the potential effects of pharmacologic treatments (recently approved for obesity) and endoscopically deployed devices on quantitative GI traits in development for obesity treatment.

METHODS

We conducted a review of relevant literature to achieve our objectives.

RESULTS

The 2013 guidelines increased the number of adults recommended for weight loss treatment by 20.9% (116.0 million to 140.2 million). There is an imbalance between efficacy and costs of commercial weight loss programs and drug therapy (average weight loss about 5 kg). The number of bariatric procedures performed in the United States has doubled in the past decade. The efficacy of bariatric surgery is attributed to reduction in the volume of the stomach, nutrient malabsorption with some types of surgery, increased postprandial incretin responses, and activation of farnesoid X receptor mechanisms. These GI and behavioral traits identify sub-phenotypes of obesity, based on recent research.

CONCLUSIONS

The mechanisms or traits targeted by drug and device treatments include centrally mediated alterations of appetite or satiation, diversion of nutrients, and alteration of stomach capacity, gastric emptying, or incretin hormones. Future treatment may be individualized based on quantitative GI and behavioral traits measured in obese patients.

Differential effects of bupropion on acquisition and performance of an active avoidance task in male mice

Bupropion is an antidepressant drug that is known to aid smoking cessation, although little experimental evidence exists about its actions on active avoidance learning tasks. Our aim was to evaluate the effects of this drug on two-way active avoidance conditioning. In this study, NMRI mice received bupropion (10, 20 and 40mg/kg) or saline before a daily training session (learning phase, days 1-4) in the active avoidance task. Performance was evaluated on the fifth day (retention phase): in each bupropion-treated group half of the mice continued with the same dose of bupropion, and the other half received saline. Among the vehicle-treated mice, different sub-groups were challenged with different doses of bupropion. Results indicated that mice treated with 10 and 20mg/kg bupropion exhibited more number of avoidances during acquisition. The response latency confirmed this learning improvement, since this parameter decreased after bupropion administration. No differences between groups were observed in the retention phase. In conclusion, our data show that bupropion influences the learning process during active avoidance conditioning, suggesting that this drug can improve the control of emotional responses.

Putting the brakes on the "drive to eat": Pilot effects of naltrexone and reward-based eating on food cravings among obese women

PURPOSE

Obese individuals vary in their experience of food cravings and tendency to engage in reward-driven eating, both of which can be modulated by the neural reward system rather than physiological hunger. We examined two predictions in a sample of obese women: (1) whether opioidergic blockade reduced food-craving intensity, and (2) whether opioidergic blockade reduced an association between food-craving intensity and reward-driven eating, which is a trait-like index of three factors (lack of control over eating, lack of satiation, preoccupation with food).

METHODS

Forty-four obese, pre-menopausal women completed the Reward-Based Eating Drive (RED) scale at study start and daily food-craving intensity on 5 days on which they ingested either a pill-placebo (2 days), a 25 mg naltrexone dose (1 day), or a standard 50mg naltrexone dose (2 days).

RESULTS

Craving intensity was similar under naltrexone and placebo doses. The association between food-craving intensity and reward-driven eating significantly differed between placebo and 50mg naltrexone doses. Reward-driven eating and craving intensity were significantly positively associated under both placebo doses. As predicted, opioidergic blockade (for both doses 25mg and 50mg naltrexone) reduced the positive association between reward-driven eating and craving intensity to non-significance.

CONCLUSIONS

Opioidergic blockade did not reduce craving intensity; however, blockade reduced an association between trait-like reward-driven eating and daily food-craving intensity, and may help identify an important endophenotype within obesity.

Integration of reward signalling and appetite regulating peptide systems in the control of food-cue responses

Understanding the neurobiological substrates that encode learning about food-associated cues and how those signals are modulated is of great clinical importance especially in light of the worldwide obesity problem. Inappropriate or maladaptive responses to food-associated cues can promote over-consumption, leading to excessive energy intake and weight gain. Chronic exposure to foods rich in fat and sugar alters the reinforcing value of foods and weakens inhibitory neural control, triggering learned, but maladaptive, associations between environmental cues and food rewards. Thus, responses to food-associated cues can promote cravings and food-seeking by activating mesocorticolimbic dopamine neurocircuitry, and exert physiological effects including salivation. These responses may be analogous to the cravings experienced by abstaining drug addicts that can trigger relapse into drug self-administration. Preventing cue-triggered eating may therefore reduce the over-consumption seen in obesity and binge-eating disorder. In this review we discuss recent research examining how cues associated with palatable foods can promote reward-based feeding behaviours and the potential involvement of appetite-regulating peptides including leptin, ghrelin, orexin and melanin concentrating hormone. These peptide signals interface with mesolimbic dopaminergic regions including the ventral tegmental area to modulate reactivity to cues associated with palatable foods. Thus, a novel target for anti-obesity therapeutics is to reduce non-homeostatic, reward driven eating behaviour, which can be triggered by environmental cues associated with highly palatable, fat and sugar rich foods.