Naltrexone-bupropion (Mysimba) in management of obesity: A systematic review and meta-analysis of unpublished clinical study reports

Obesity and cardiovascular disease: an ESC clinical consensus statement

The global prevalence of obesity has more than doubled over the past four decades, currently affecting more than a billion individuals. Beyond its recognition as a high-risk condition that is causally linked to many chronic illnesses, obesity has been declared a disease per se that results in impaired quality of life and reduced life expectancy. Notably, two-thirds of obesity-related excess mortality is attributable to cardiovascular disease. Despite the increasingly appreciated link between obesity and a broad range of cardiovascular disease manifestations including atherosclerotic disease, heart failure, thromboembolic disease, arrhythmias, and sudden cardiac death, obesity has been underrecognized and sub-optimally addressed compared with other modifiable cardiovascular risk factors. In the view of major repercussions of the obesity epidemic on public health, attention has focused on population-based and personalized approaches to prevent excess weight gain and maintain a healthy body weight from early childhood and throughout adult life, as well as on comprehensive weight loss interventions for persons with established obesity. This clinical consensus statement by the European Society of Cardiology discusses current evidence on the epidemiology and aetiology of obesity; the interplay between obesity, cardiovascular risk factors and cardiac conditions; the clinical management of patients with cardiac disease and obesity; and weight loss strategies including lifestyle changes, interventional procedures, and anti-obesity medications with particular focus on their impact on cardiometabolic risk and cardiac outcomes. The document aims to raise awareness on obesity as a major risk factor and provide guidance for implementing evidence-based practices for its prevention and optimal management within the context of primary and secondary cardiovascular disease prevention.

Obesity and cardiovascular disease: an ESC clinical consensus statement

The global prevalence of obesity has more than doubled over the past four decades, currently affecting more than a billion individuals. Beyond its recognition as a high-risk condition that is causally linked to many chronic illnesses, obesity has been declared a disease per se that results in impaired quality of life and reduced life expectancy. Notably, two-thirds of obesity-related excess mortality is attributable to cardiovascular disease. Despite the increasingly appreciated link between obesity and a broad range of cardiovascular disease manifestations including atherosclerotic disease, heart failure, thromboembolic disease, arrhythmias, and sudden cardiac death, obesity has been underrecognized and sub-optimally addressed compared with other modifiable cardiovascular risk factors. In the view of major repercussions of the obesity epidemic on public health, attention has focused on population-based and personalized approaches to prevent excess weight gain and maintain a healthy body weight from early childhood and throughout adult life, as well as on comprehensive weight loss interventions for persons with established obesity. This clinical consensus statement by the European Society of Cardiology discusses current evidence on the epidemiology and aetiology of obesity; the interplay between obesity, cardiovascular risk factors and cardiac conditions; the clinical management of patients with cardiac disease and obesity; and weight loss strategies including lifestyle changes, interventional procedures, and anti-obesity medications with particular focus on their impact on cardiometabolic risk and cardiac outcomes. The document aims to raise awareness on obesity as a major risk factor and provide guidance for implementing evidence-based practices for its prevention and optimal management within the context of primary and secondary cardiovascular disease prevention.

Treatment with liraglutide or naltrexone-bupropion in patients with genetic obesity: a real-world study

Background

Rare genetic obesity commonly features early-onset obesity, hyperphagia, and therapy-resistance to lifestyle interventions. Pharmacotherapy is often required to treat hyperphagia and induce weight loss. We describe clinical outcomes of glucagon-like peptide-1 analogue liraglutide or naltrexone-bupropion treatment in adults with molecularly confirmed genetic obesity (MCGO) or highly suspected for genetic obesity without definite diagnosis (HSGO).

Methods

We conducted a real-world cohort study at the Obesity Center CGG at Erasmus University Center, Rotterdam, Netherlands, between March 19, 2019, and August 14, 2023. All patients with MCGO and HSGO who were treated with either liraglutide or naltrexone-bupropion were included. Liraglutide 3 mg and naltrexone-bupropion were administered according to the manufacturer's protocol. Treatment evaluation occurred short-term, after 12 weeks on maximum or highest-tolerated dose, preceded by the 4-5 week dose escalation phase. Differences in anthropometrics, body composition, metabolic markers, self-reported appetite, eating behaviour, and quality of life (QoL) were evaluated.

Findings

Ninety-eight adults were included in the analysis: 23 patients with MCGO and 75 patients with HSGO, with median BMI of 42.0 kg/m2 (IQR 38.7-48.2) and 43.7 kg/m2 (IQR 38.0-48.7), respectively. After liraglutide treatment, median weight at evaluation significantly decreased compared to baseline in both groups: -4.7% (IQR -6.0 to -1.5) in patients with MCGO and -5.2% (IQR -8.1 to -3.5) in patients with HSGO. Additionally, improvements were observed in appetite, fat mass, fasting glucose, and HbA1c in both patients with MCGO and with HSGO. Patients with HSGO also reported significant improvements in several domains of QoL and eating behaviour. In patients with MCGO and HSGO treated with naltrexone-bupropion, mean weight at evaluation significantly differed from baseline: -5.2% ± 5.8 in patients with MCGO and -4.4% ± 4.7 in patients with HSGO. Appetite, fat mass, and waist circumference significantly decreased in both groups. Obesity-related comorbidities improved in significant proportions of patients treated with liraglutide or naltrexone-bupropion.

Interpretation

In conclusion, our short-term findings show potential of liraglutide and naltrexone-bupropion as treatment options for adults with (a clinical phenotype of) genetic obesity.

Funding

MB, EvdA, and EvR are supported by the Elisabeth Foundation, a non-profit foundation supporting academic obesity research.

The Effect of KSK-94, a Dual Histamine H3 and Sigma-2 Receptor Ligand, on Adipose Tissue in a Rat Model of Developing Obesity

BACKGROUND

Numerous studies highlight the critical role that neural histamine plays in feeding behavior, which is controlled by central histamine H3 and H1 receptors. This is the fundamental motivation for the increased interest in creating histamine H3 receptor antagonists as anti-obesity medications. On the other hand, multiple other neurotransmitter systems have been identified as pharmacotherapeutic targets for obesity, including sigma-2 receptor systems. Interestingly, in our previous studies in the rat excessive eating model, we demonstrated a significant reduction in the development of obesity using dual histamine H3/sigma-2 receptor ligands. Moreover, we showed that compound KSK-94 (structural analog of Abbott's A-331440) reduced the number of calories consumed, and thus acted as an anorectic compound. Therefore, in this study, we extended the previous research and studied the influence of KSK-94 on adipose tissue collected from animals from our previous experiment.

METHODS

Visceral adipose tissue was collected from four groups of rats (standard diet + vehicle, palatable diet + vehicle, palatable diet + KSK-94, and palatable diet + bupropion/naltrexone) and subjected to biochemical, histopathological, and immunohistochemical studies.

RESULTS

The obtained results clearly indicate that compound KSK-94 prevented the hypertrophy and inflammation of visceral adipose tissue, normalized the levels of leptin, resistin and saved the total reduction capacity of adipose tissue, being more effective than bupropion/naltrexon in these aspects. Moreover, KSK-94 may induce browning of visceral white adipose tissue.

CONCLUSION

Our study suggests that dual compounds with a receptor profile like KSK-94, i.e., targeting histamine H3 receptor and, to a lesser extent, sigma-2 receptor, could be attractive therapeutic options for patients at risk of developing obesity or with obesity and some metabolic disorders. However, more studies are required to determine its safety profile and the exact mechanism of action of KSK-94.

Pharmacological treatment of non-responders following bariatric surgery

Obesity is a complex chronic disease and requires a long-term multidisciplinary management. Even patients undergoing bariatric surgery, one the most effective treatments for obesity, can have insufficient weight loss (IWL) than expected (primary non responder) or weight regain (WR) after a successful primary procedure (secondary non responder). A poor response represents a challenge of bariatric surgery that can induce persistence or recurrence of obesity-related comorbidities, prejudicing benefits of surgery. Increasing evidence suggests that weight loss medications represent a useful strategy in obesity care also after bariatric surgery procedures. This narrative review summarizes the evidence concerning anti-obesity therapy in the management of no-responders to primary bariatric surgery. Available data on liraglutide (one randomized double-blind placebo-controlled trial, three prospective and three retrospective studies), naltrexone/bupropion (three retrospective studies), orlistat (one case control prospective and one retrospective studies) and topiramate and phentermine (five retrospective studies) have been considered. Available data suggest that weight loss medications could offer a significant adjunctive benefit to lifestyle and behavioral modifications in the life-long management of obesity. Newer treatment modalities including the use of anti-obesity drugs provide patients and healthcare providers with more options in the management of poor response after bariatric surgery.

Consensus on pharmacological treatment of obesity in Latin America

A panel of 10 experts in obesity from various Latin American countries held a Zoom meeting intending to reach a consensus on the use of anti-obesity medicines and make updated recommendations suitable for the Latin American population based on the available evidence. A questionnaire with 16 questions was developed using the Patient, Intervention, Comparison, Outcome (Result) methodology, which was iterated according to the modified Delphi methodology, and a consensus was reached with 80% or higher agreement. Failure to reach a consensus led to a second round of analysis with a rephrased question and the same rules for agreement. The recommendations were drafted based on the guidelines of the American College of Cardiology Foundation/American Heart Association Task Force on Practice. This panel of experts recommends drug therapy in patients with a body mass index of ≥30 or ≥27 kg/m2 plus at least one comorbidity, when lifestyle changes are not enough to achieve the weight loss objective; alternatively, lifestyle changes could be maintained while considering individual parameters. Algorithms for the use of long-term medications are suggested based on drugs that increase or decrease body weight, results, contraindications, and medications that are not recommended. The authors concluded that anti-obesity treatments should be individualized and multidisciplinary.

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.

Integration of Endogenous Opioid System Research in the Interprofessional Diagnosis and Treatment of Obesity and Eating Disorders

This third and final chapter in our trilogy introduces the clinical distinctions and phenotypical similarities between obesity and eating disorders. Research elaborating on the shared neurobiological substrates for obesity and eating disorders is discussed. We present an interprofessional model of treatment for both disordered eating and for obesity. Additionally, this chapter establishes the translational importance of research connecting endogenous opioid activity with both obesity and eating disorders, with an emphasis on clinical interventions. We conclude with a discussion of future directions for research.

Genetic underpinning of the comorbidity between type 2 diabetes and osteoarthritis

Multimorbidity is a rising public health challenge with important implications for health management and policy. The most common multimorbidity pattern is the combination of cardiometabolic and osteoarticular diseases. Here, we study the genetic underpinning of the comorbidity between type 2 diabetes and osteoarthritis. We find genome-wide genetic correlation between the two diseases and robust evidence for association-signal colocalization at 18 genomic regions. We integrate multi-omics and functional information to resolve the colocalizing signals and identify high-confidence effector genes, including FTO and IRX3, which provide proof-of-concept insights into the epidemiologic link between obesity and both diseases. We find enrichment for lipid metabolism and skeletal formation pathways for signals underpinning the knee and hip osteoarthritis comorbidities with type 2 diabetes, respectively. Causal inference analysis identifies complex effects of tissue-specific gene expression on comorbidity outcomes. Our findings provide insights into the biological basis for the type 2 diabetes-osteoarthritis disease co-occurrence.

Cost-effectiveness analysis of five anti-obesity medications from a US payer's perspective

BACKGROUND AND AIMS

To determine the cost-effectiveness of anti-obesity medications (AOM): tirzepatide, semaglutide, liraglutide, phentermine plus topiramate (PpT), and naltrexone plus bupropion (NpB).

METHODS AND RESULTS

From a U.S. perspective we developed a Markov model to simulate weight change over a 40-year time horizon using results from clinical studies. According to the body mass index (BMI), cardiovascular diseases, diabetes and mortality risk were the health states considered in the model, being mutually exclusive. Costs of AOM, adverse events, cardiovascular events, and diabetes were included. We applied a 3% per-year discount rate and calculated the incremental cost-effectiveness ratios (ICERs) of cost per quality-adjusted life-year (QALY) gained. Probabilistic sensitivity analyses incorporated uncertainty in input parameters. A deterministic analysis was conducted to determine the robustness of the model. The model included a cohort of 78.2% females with a mean age of 45 years and BMI of 37.1 (SD 4.9) for females and 36.8 (SD 4.9) for males. NpB and PpT were the least costly medications and, all medications differed no more than 0.5 QALYs. Tirzepatide ICER was $355,616 per QALY. Liraglutide and semaglutide options were dominated by PpT.

CONCLUSION

Compared to other AOM, PpT was lowest cost treatment with nearly identical QALYs with other agents.

Metabolic and bariatric surgery and obesity pharmacotherapy for cancer prevention: current status and future possibilities

Obesity is a chronic, relapsing, progressive disease of excess adiposity that increases the risk of developing at least 13 types of cancer. This report provides a concise review of the current state of the science regarding metabolic and bariatric surgery and obesity pharmacotherapy related to cancer risk. Meta-analyses of cohort studies report that metabolic and bariatric surgery is independently associated with a lower risk of incident cancer than nonsurgical obesity care. Less is known regarding the cancer-preventive effects of obesity pharmacotherapy. The recent approval and promising pipeline of obesity drugs will provide the opportunity to understand the potential for obesity therapy to emerge as an evidence-based cancer prevention strategy. There are myriad research opportunities to advance our understanding of how metabolic and bariatric surgery and obesity pharmacotherapy may be used for cancer prevention.

Pharmacotherapy of obesity: an update on the available medications and drugs under investigation

Obesity is an epidemic and a public health threat. Medical weight management remains one of the options for the treatment of excess weight and recent advances have revolutionized how we treat, and more importantly how we will be treating obesity in the near future. Metreleptin and Setmelanotide are currently indicated for rare obesity syndromes, and 5 other medications (orlistat, phentermine/topiramate, naltrexone/bupropion, liraglutide, semaglutide) are approved for non-syndromic obesity. Tirzepatide is about to be approved, and other drugs, with exciting novel mechanisms of action primarily based on incretins, are currently being investigated in different phases of clinical trials. The majority of these compounds act centrally, to reduce appetite and increase satiety, and secondarily, in the gastrointestinal tract to slow gastric emptying. All anti-obesity medications improve weight and metabolic parameters, with variable potency and effects depending on the specific drug. The currently available data do not support a reduction in hard cardiovascular outcomes, but it is almost certain that such data are forthcoming in the very near future. The choice of the anti-obesity medication needs to take into consideration the patient's clinical and biochemical profile, co-morbidities, and drug contra-indications, as well as expected degree of weight loss and improvements in cardio-renal and metabolic risk. It also remains to be seen whether precision medicine may offer personalized solutions to individuals with obesity, and whether it may represent the future of medical weight management along with the development of novel, very potent, anti-obesity medications currently in the pipeline.

Funding

None.

Fat fighting liraglutide based nano-formulation to reverse obesity: Design, development and animal trials

Obesity is a metabolic disease, which is one of the major causes of morbidity and mortality, where therapeutic options are limited. Treatment of obesity is necessary as it is associated with fatal complications like diabetes mellitus, cardiovascular disease, non-alcoholic fatty liver disease, osteoarthritis, and many more. Liraglutide (Lir), a synthetic analogue of Glucagon-like Peptide-1 (GLP-1), is the FDA approved anti-obesity drug, however, its major limitation is its clinical application which needs frequent parenteral injections. To address the issue of regular injection, we have synthesized a fat fighting oral nano-formulation of liraglutide with a sustained release feature, which was evaluated against high fat diet (HFD) induced obesity in mice. Experimental obesity was induced in mice by feeding HFD for 26 weeks. Lir nanoparticles (NP) were fabricated with chitosan via ion-gelation technique and were coated with Eudragit@S100 to protect the drug in harsh gastric conditions. Physiochemical characterization of Eu-Lir-Cs-NP demonstrated a small particle size of 253.1 ± 1.21 nm with ∼ 9.74 % loading and ∼ 72.11 % encapsulation efficiency of the drug. In-vitro studies showed successful cellular uptake of NP in Caco-2 cells and were stable in various enteric fluid pH conditions. Eudragit@S100 coated chitosan NP were able to protect the drug from harsh gastric pH conditions with more than ∼ 74% of recovery. Treatment of two weeks of liraglutide Eu-Lir-Cs-NP (0.1, 0.2 and 0.4 mg/kg, orally; twice daily) moderately reduces obesity in mice as evidenced by a reduction in the body weight, blood glucose, serum total cholesterol, serum triglyceride, serum resistin and serum insulin level of mice. In addition, significant reduction of liver weight, abdominal white adipose tissue, and hepatic oxidative stress were noted. Our results suggest that chitosan-based NP of liraglutide can be an effective and convenient formulation for the management of obesity.

Metabolically Healthy Obesity: Are Interventions Useful?

PURPOSE OF REVIEW

This review aims to detail the current global research state of metabolically healthy obesogenesis with regard to metabolic factors, disease prevalence, comparisons to unhealthy obesity, and targeted interventions to reverse or delay progression from metabolically healthy to unhealthy obesity.

RECENT FINDINGS

As a long-term condition with increased risk of cardiovascular, metabolic, and all-cause mortality risks, obesity threatens public health on a national level. The recent discovery of metabolically healthy obesity (MHO), a transitional condition during which obese persons carry comparatively lower health risks, has added to confusion about the true effect of visceral fat and subsequent long-term health risks. In this context, the evaluation of fat loss interventions, such as bariatric surgery, lifestyle changes (diet/exercise), and hormonal therapies require re-evaluation in light of evidence that progression to high-risk stages of obesity relies on metabolic status and that strategies to protect the metabolism may be useful in the prevention of metabolically unhealthy obesity. Typical calorie-based exercise and diet interventions have failed to reduce the prevalence of unhealthy obesity. Holistic lifestyle, psychological, hormonal, and pharmacological interventions for MHO, on the other hand, may at least prevent progression to metabolically unhealthy obesity.

Dissolution Assay of Bupropion/Naltrexone Hydrochloride Salts of Bilayer Composition Tablets Following the Development and Validation of a Novel HPLC Method

Compounded medicinal products containing bupropion hydrochloride (BUP·HCl) and naltrexone hydrochloride (NTX·HCl) are available as adjunct therapy for the management of weight in obese/overweight adults. The present work describes the development and validation of a novel RP-HPLC method for a simultaneous quantitation during the dissolution of both drugs from compounded bilayer composition tablets. The method involves a Nucleosil 100-3 C-18 column (4.6 × 150 mm) and a mobile phase of a 70%/30% v/v ACN/KH₂PO₄·H₂O aqueous solution of a 5 mM concentration. The flow rate was set at 1.35 mL/min and the detection was conducted using UV spectrophotometry (λ_max 214 nm). The method was validated according to the ICH guidelines and fulfilled the specifications for the specificity, linearity, accuracy, precision and stability for both the sample and standard solutions. Furthermore, the robustness of the method was evaluated by applying a fractional factorial experimental design and by utilizing both graphical and statistical approaches to identify the HPLC factors that should be strictly controlled during the analysis. The method proved to be suitable for the analysis of the dissolution samples and, consequently, the release of BUP·HCl and NTX·HCl from the formulations.

A narrative review of anti-obesity medications for obese patients with osteoarthritis

INTRODUCTION

: The prevalence of both obesity and osteoarthritis (OA) are increasing worldwide (twindemic), and the association between the two chronic diseases is also well-established.

AREAS COVERED

: In this narrative review, we will briefly describe the double burdens of both diseases, the impact of weight loss or gain on OA incidence and structural progression and discuss the biomechanical and anti-inflammatory mechanisms mediating these effects. FDA-approved anti-obesity drugs are summarized in terms of their clinical efficacy and safety profile, and the completed or ongoing phase 2/3 clinical trials of such drugs in OA patients with obesity are examined.

EXPERT OPINION

: We will discuss the perspectives related to principles of prescription of anti-obesity drugs, the potential role of phenotype-guided approach, time to drug effects in clinical trials, sustainability of weight loss based on the real-world studies, the importance of concomitant therapies such as dieting and exercises, and the role of weight loss on non-weight bearing OA joints. Although obesity is the major risk factor for OA pathogenesis and progression, and there are a variety of anti-obesity medications on the market, research on the use of these disease-modifying drugs in OA (DMOAD) is still sparse..

Cardiovascular safety of naltrexone and bupropion therapy: Systematic review and meta-analyses

Despite being approved for clinical use, evidence of cardiovascular safety (CV) is lacking for treatment with bupropion, naltrexone, or their combination (B-N). The purpose of the study is to determine the relationship between these treatments and the risk of major cardiovascular adverse events (MACE). Phase 3 randomized clinical trials (RCT) evaluating bupropion, naltrexone, or B-N versus control with reported incidence of MACE. The meta-analysis included 12 RCTs, 69% for weight loss and 29% for smoking cessation, with 19,176 patients and 7354 patient-years who were randomized to an active treatment (bupropion [n = 2965] or B-N [n = 6980] or naltrexone [n = 249]) versus control (placebo [n = 6968] or nicotine patch [n = 2014]). The mean age was 54 ± 8 years (55% female), and the baseline BMI was 32 ± 5 kg/m² . The additive network meta-analysis model for random effects showed no association between bupropion, B-N, or naltrexone and MACE (odds ratio [OR] = 0.90 [95%CI 0.65-1.25], p = 0.52; OR = 0.97 [95%CI 0.75-1.24], p = 0.79; OR = 1.08 [95%CI 0.71-1.63], p = 0.73, respectively; I² = 0%, p = 0.86). Meta-regression analyses showed no significant association between MACE and potential confounders from RCT demographic disparities (p = 0.58). The statistical power (post hoc two-tailed) for non-inferiority was 91%, giving a strong probability of validity. Naltrexone, bupropion, or B-N is not associated with the incidence of MACE as compared with placebo.

Efficacy and Safety of Phentermine/Topiramate in Adults with Overweight or Obesity: A Systematic Review and Meta-Analysis

OBJECTIVE

The study objective was to examine the association between phentermine/topiramate therapy and weight loss and adverse events in adults with overweight or obesity by meta-analysis and systematic review.

METHODS

Medical Subject Headings and free-text terms were selected to search for eligible trials in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Embase up to April 18, 2020. The quality of randomized controlled trials was evaluated by the Cochrane risk-of-bias tool. Meta-analysis was performed using random-effect models.

RESULTS

Phentermine/topiramate therapy resulted in an average weight loss of 7.73 kg (95% CI: 6.60-8.85) in general compared with placebo. The weight loss was related to the dose of phentermine/topiramate. Compared with placebo, the average weight loss was 3.55 kg (95% CI: 2.22-4.88) for 3.75/23 mg, 7.27 kg (95% CI: 6.40-8.13) for 7.5/46 mg, and 8.25 kg (95% CI: 6.92-9.79) for 15/92 mg. For phentermine/topiramate participants in different weight-loss subgroups, the weight loss of participants with ≥5%, ≥10%, and ≥15% baseline weight loss was 3.18 (95% CI: 2.75-3.67), 5.32 (95% CI: 4.53-6.25), and 5.65 (95% CI: 3.55-9.01), respectively. Compared with placebo, the adverse events associated with the treatment mainly included dysgeusia (odds ratio [OR] = 8.86, 95% CI: 5.65-13.89), paresthesia (OR = 8.51, 95% CI: 6.20-11.67), dry mouth (OR = 6.71, 95% CI: 5.03-8.94), disturbance in attention (OR = 4.48, 95% CI: 2.39-8.41), irritability (OR = 4.10, 95% CI: 2.29-7.33), hypoesthesia (OR = 3.81, 95% CI: 1.32-11.00), constipation (OR = 2.43, 95% CI: 2.02-2.93), and dizziness (OR = 2.26, 95% CI: 1.72-2.98). Phentermine/topiramate also reduced waist circumference, blood pressure, blood sugar levels, and lipid levels.

CONCLUSIONS

Phentermine/topiramate has considerable benefit in reducing body weight, and the efficacy was closely related to the dosage. However, it increased the risk of nervous system-related adverse events.

Mesolimbic opioid-dopamine interaction is disrupted in obesity but recovered by weight loss following bariatric surgery

Obesity is a growing burden to health and the economy worldwide. Obesity is associated with central µ-opioid receptor (MOR) downregulation and disruption of the interaction between MOR and dopamine D₂ receptor (D₂R) system in the ventral striatum. Weight loss recovers MOR function, but it remains unknown whether it also recovers aberrant opioid-dopamine interaction. Here we addressed this issue by studying 20 healthy non-obese and 25 morbidly obese women (mean BMI 41) eligible for bariatric surgery. Brain MOR and D₂R availability were measured using positron emission tomography (PET) with [¹¹C]carfentanil and [¹¹C]raclopride, respectively. Either Roux-en-Y gastric bypass or sleeve gastrectomy was performed on obese subjects according to standard clinical treatment. 21 obese subjects participated in the postoperative PET scanning six months after bariatric surgery. In the control subjects, MOR and D₂R availabilities were associated in the ventral striatum (r = .62) and dorsal caudate (r = .61). Preoperatively, the obese subjects had disrupted association in the ventral striatum (r = .12) but the unaltered association in dorsal caudate (r = .43). The association between MOR and D₂R availabilities in the ventral striatum was recovered (r = .62) among obese subjects following the surgery-induced weight loss. Bariatric surgery and concomitant weight loss recover the interaction between MOR and D₂R in the ventral striatum in the morbidly obese. Consequently, the dysfunctional opioid-dopamine interaction in the ventral striatum is likely associated with an obese phenotype and may mediate excessive energy uptake. Striatal opioid-dopamine interaction provides a feasible target for pharmacological and behavioral interventions for treating obesity.

Understanding the appetite modulation pathways: The role of the FFA1 and FFA4 receptors

Pharmaconutrition is an area of current interest, especially concerning the advances in the pharmacology of nutrient-sensing receptors, as have been accomplished in the last 20 years. The family of free fatty acid (FFA) receptors is composed of four members, sequentially named as FFA1 to FFA4, which are activated by the short to long-chain fatty acids. The affinity of the FFA1 and FFA4 receptors for the omega-3 polyunsaturated fatty acids prompted pre-clinical and clinical investigations regarding their involvement in metabolic diseases. The main studies have been focused on the receptors' expression analyses, the featuring of knockout mice, and the assessment of selective synthetic ligands. These clearly have indicated a relevant role for FFA1 and FFA4 in the peripheral and central circuits for the regulation of energetic metabolism. This review article aimed to discuss the relevance of the FFA1 and FFA4 receptors in appetite-related complications, mainly related to obesity, cancer cachexia, and anorexia in the elderly, emphasizing whether their pharmacological modulation might be useful for the management of these disorders.

Naltrexone-bupropion (Mysimba) in management of obesity: A systematic review and meta-analysis of unpublished clinical study reports

AIMS

To compare the benefits and harms of naltrexone-bupropion using evidence from clinical study reports.

METHODS

We searched Food and Drug Administration and European Medicines Agency websites, PubMed, and Clinicaltrials.gov (May 2016) to identify pivotal trials; we then sent a freedom of information request to the European Medicines Agency (July 2016). We included pivotal, phase III placebo-controlled trials. We assessed the risks of bias using the Cochrane criteria, and the quality of the evidence using GRADE. We used a random-effects model for meta-analyses.

RESULTS

Over a 27-month period (July 2016 to August 2018), we received 31 batches of clinical study report documents containing over 65 000 pages of data from 4 pivotal trials (n = 4536). Significantly more participants who took naltrexone-bupropion achieved ≥5% reduction in body weight: risk ratio (RR) = 2.1 (95% confidence interval 1.35-3.28), P = .001, GRADE = low, number needed to treat (NNT) to benefit = 5 (3-17); this represents a 2.53 kg (1.85-3.21) reduction in baseline body weight compared with placebo. Naltrexone-bupropion had significantly beneficial effects on other cardiovascular risk factors; however, the true effect sizes for these are uncertain because of incomplete outcome data. Naltrexone-bupropion significantly increased the risk of adverse events: RR = 1.11 (1.05-1.18, P = .0004, GRADE = low, NNT to harm = 12 7-27); serious adverse events: RR = 1.70 (1.38-2.1, P < .00001, GRADE = moderate, NNT to harm = 21 13-38); and discontinuation because of adverse events: RR = 1.92 (1.65-2.24, P < .00001, GRADE = moderate, NNT to discontinue treatment = 9 8-13).

CONCLUSIONS

Naltrexone-bupropion significantly reduces body weight by a small amount but significantly increases the risk of adverse events. A rigorous process of postmarketing surveillance is required.