Bupropion SR vs. placebo for weight loss in obese patients with depressive symptoms

The effects of bupropion alone and combined with naltrexone on weight loss: a systematic review and meta-regression analysis of randomized controlled trials

BACKGROUND

The global prevalence of obesity and overweight is a significant concern in the field of public health. However, addressing and combating these conditions pose considerable challenges. Numerous interventional studies have been conducted to assess the possible impact of bupropion on weight reduction. The primary objective of this study was to conduct a comprehensive investigation into the effects of bupropiona alone and in combination with naltrexone on weight, body mass index (BMI), and waist circumferences (WC).

METHODS

A systematic search was conducted in five databases using established keywords. The purpose of this search was to uncover controlled trials that examined the impact of bupropion, either as a standalone intervention or in combination with naltrexone, on weight loss outcomes. The random-effects model analysis was used to provide pooled weighted mean difference and 95% confidence intervals.

RESULTS

Twenty five studies with 22,165 participants' were included in this article. The pooled findings showed that bupropion administration has an effect on lowering weight (WMD: -3.67 kg, 95% CI: -4.43 to -2.93) and WC (WMD: -2.98 cm, 95% CI -3.78 to -2.19) in compared with control groups. The analysis also showed that the effects of the present intervention on weight and WC during the intervention are > 26 weeks and ≤ 26 weeks compared to the other group, respectively. In addition, changes in weight loss and WC after receiving bupropion together with naltrexone were more compared to bupropion alone.

CONCLUSIONS

In conclusion, the addition of combination therapies like bupropion and naltrexone to lifestyle modifications including diet would cause significant weight loss.

Changes in lipid profile and glucose metabolism following administration of bupropion alone or in combination with naltrexone: A systematic review and meta-regression analysis

BACKGROUND

Considering the conflicting effects of bupropion on parameters related to metabolic syndrome including glucose metabolism and lipid profile, in this meta-analysis study, we investigated the effects of this drug alone or in combination with naltrexone on glucose metabolism and lipid profile.

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 glucose and lipid profile. Pooled weighted mean difference and 95% confidence intervals were achieved by random-effects model.

RESULTS

Twelve studies with 5152 participants' were included in this article. The pooled findings showed that bupropion alone or in combination with naltrexone would significantly reduce glucose (weighted mean difference (WMD): -2.25 mg/dL, 95% confidence interval (CI): -4.10, -0.40), insulin (WMD: -4.06 μU/mL, 95% CI: -6.09, -2.03), homeostatic model assessment for insulin resistance (HOMA-IR) (WMD: -0.58, 95% CI: -0.98, -0.19), triglyceride (TG) (WMD: -11.78 mg/dL, 95% CI: -14.48 to -9.08) and increase high-density lipoprotein (HDL) (WMD: 2.68 mg/dL, 95% CI: 2.13 to 3.24). A Greater reduction in glucose levels was observed with duration >26 weeks. Dose of bupropion intake ≤360 mg and intervention for more than 26 weeks decreased insulin level significantly. With regard to lipid profile, reduction of triglycerides is more significant with dose of bupropion greater than 360 mg and a shorter intervention length equal to 26 weeks.

CONCLUSIONS

The addition of combination therapies such as bupropion and naltrexone to lifestyle modification can significantly improve glucose metabolism and some lipid parameters.

Effectiveness and safety of drugs for obesity

Recent publicity around the use of new antiobesity medications (AOMs) has focused the attention of patients and healthcare providers on the role of pharmacotherapy in the treatment of obesity. Newer drug treatments have shown greater efficacy and safety compared with older drug treatments, yet access to these drug treatments is limited by providers' discomfort in prescribing, bias, and stigma around obesity, as well as by the lack of insurance coverage. Now more than ever, healthcare providers must be able to discuss the risks and benefits of the full range of antiobesity medications available to patients, and to incorporate both guideline based advice and emerging real world clinical evidence into daily clinical practice. The tremendous variability in response to antiobesity medications means that clinicians need to use a flexible approach that takes advantage of specific features of the antiobesity medication selected to provide the best option for individual patients. Future research is needed on how best to use available drug treatments in real world practice settings, the potential role of combination therapies, and the cost effectiveness of antiobesity medications. Several new drug treatments are being evaluated in ongoing clinical trials, suggesting that the future for pharmacotherapy of obesity is bright.

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.

A phenotypic approach to obesity treatment

Obesity is a chronic disease that increases morbidity and mortality and adversely affects quality of life. The rapid rise of obesity has outpaced the development and deployment of effective therapeutic interventions, thereby creating a global health crisis. The presentation, complications, and response to obesity treatments vary, yet lifestyle modification, which is the foundational therapeutic intervention for obesity, is often "one size fits all." The concept of personalized medicine uses genetic and phenotypic information as a guide for disease prevention, diagnosis, and treatment and has been successfully applied in diseases such as cancer, but not in obesity. As we gain insight into the pathophysiologic mechanisms of obesity and its phenotypic expression, specific pathways can be targeted to yield a greater, more sustained therapeutic impact in an individual patient with obesity. A phenotype-based pharmacologic treatment approach utilizing objective measures to classify patients into predominant obesity mechanism groups resulted in greater weight loss (compared with a non-phenotype-based approach) in a recent study by Acosta and colleagues. In this review, we discuss the application of lifestyle modifications, behavior therapy and pharmacotherapy using the obesity phenotype-based approach as a framework.

Initiating Pharmacologic Treatment in Tobacco-Dependent Adults

There is a strong evidence base for the use of existing pharmacotherapies to support tobacco cessation, alone or in combination, ideally with concurrent behavioral interventions. Future pharmacotherapies under development may assist in the most refractory cases. Incorporating current and future therapies into a longitudinal chronic care model for tobacco dependence will help a diverse range of patients achieve independence from nicotine addiction.

Weight-centric treatment of depression and chronic pain

BACKGROUND

Depression and chronic pain are two major chronic non-communicable diseases (CNCD). Considering the bidirectional relationship between obesity and CNCD, it is of the utmost importance to understand the effect of medications utilized to treat these diseases on body weight.

METHODS

This is a clinical review on the effect of medications for depression and chronic pain on body weight. We searched PubMed, Scopus, MEDLINE, and Google Scholar databases for studies on the topic from January 1, 1950 to April 1, 2022 in English language. Additionally, we present expert opinions in the fields of obesity, depression and chronic pain, providing a weight-centric approach to treat depression and chronic pain.

RESULTS

Several antidepressant and chronic pain medications are associated with weight gain. Selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, tricyclic antidepressants, monoamine oxidases, mirtazapine and trazodone are common antidepressants that can increase body weight while bupropion is significantly associated with weight loss. Gabapentin and pregabalin are common chronic pain medications that are linked to weight gain. On the other hand, topiramate is associated with significant weight loss. Obesity, depression and chronic pain experts recommend avoiding medications that can increase body weight if another effective alternative is available.

CONCLUSION

By shifting prescribing practices toward a weight-conscious approach (i.e., switching from weight gain medications to weight loss/neutral), it is possible to mitigate the incidence of drug-induced weight gain.

Historical and cultural aspects of obesity: From a symbol of wealth and prosperity to the epidemic of the 21st century

World Health Organization defines obesity as abnormal or excess adipose tissue accumulation. Nowadays, this condition is a serious threat to the public health in most countries around the world. Obesity adversely affects physical, mental, and in most cultures, social well-being. However, throughout the ages-from ancient times to the 21st century-this condition has been subject to various interpretations. As a matter of fact, obesity has not always been regarded as a disease. For many decades, excessive body weight has been considered rather a symbol of health. It was a marker of wealth and prosperity, as well as a sign of high social status. The centuries that passed on the development of science and medicine have gradually changed its face, but significant progress in understanding the causes and consequences of obesity has been made in the last 30 years. This paper presents the historical outline of obesity and its treatment from ancient times to the present-from its affirmation to the epidemic in the late 20th and 21st century.

Fragile X Syndrome: From Molecular Aspect to Clinical Treatment

Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by the full mutation as well as highly localized methylation of the fragile X mental retardation 1 (FMR1) gene on the long arm of the X chromosome. Children with FXS are commonly co-diagnosed with Autism Spectrum Disorder, attention and learning problems, anxiety, aggressive behavior and sleep disorder, and early interventions have improved many behavior symptoms associated with FXS. In this review, we performed a literature search of original and review articles data of clinical trials and book chapters using MEDLINE (1990-2021) and ClinicalTrials.gov. While we have reviewed the biological importance of the fragile X mental retardation protein (FMRP), the FXS phenotype, and current diagnosis techniques, the emphasis of this review is on clinical interventions. Early non-pharmacological interventions in combination with pharmacotherapy and targeted treatments aiming to reverse dysregulated brain pathways are the mainstream of treatment in FXS. Overall, early diagnosis and interventions are fundamental to achieve optimal clinical outcomes in FXS.

Avoiding hindsight in non-obviousness determination: case law review of pharmaceutical patents and guidance from the KSR v Teleflex decision

Introduction: Hindsight bias is the tendency to estimate an outcome once it is known. Legal systems are often prone to hindsight bias. In patent law, the non-obviousness or inventive step is the most critical determinant of patentability and often subjected to hindsight bias.Areas covered: Scholarly literature confirms the existence of hindsight bias in different patent systems. This communication hence addresses factors, which lead to hindsight bias specifically in chemical and pharmaceutical arts, guidance from the case law that can be helpful in avoiding hindsight bias in non-obviousness determination.Expert opinion: The Supreme Court in 2007, advocated a more expansive and flexible approach to where the Teaching Suggestion or Motivation test could come from. In the case of chemical and pharmaceutical active compounds, the considerations such as i) was there sufficient motivation to modify the lead compound and arrive at the claimed compound and its properties, ii) was there a reasonable expectation of success to achieve the claimed property and other such considerations highlighted in this review may contribute to avoid hindsight bias in non-obviousness determination.

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.

Medical Weight-Loss Outcomes in Patients Receiving Concomitant Psychotropic Medication: A Retrospective Cohort Study

OBJECTIVE

This study aimed to elucidate medical weight-loss outcomes in patients unexposed or exposed to psychotropic medication(s).

METHODS

This retrospective cohort study evaluated weight-loss outcomes of completers treated at an academic weight-management center between April 1, 2014, and April 1, 2016. Patients were classified as either unexposed (not prescribed psychotropic medication) or exposed (prescribed psychotropic medication) based on use of antidepressants, mood stabilizers, or antipsychotics during the study.

RESULTS

Of 1,932 patients seen during the study period, 885 were eligible for inclusion, of whom 619 (70.0%) were unexposed and 266 (30.0%) were exposed to psychotropic medications. In the unexposed and exposed groups, the mean age, sex distribution, proportion with type 2 diabetes, initial BMI, and number of weight-loss medications prescribed were similar. At 12 months, the unexposed group lost 1.6% more weight on average than the exposed group (9.1% [SD 7.6%] vs. 7.5% [SD 8.1%], respectively; P = 0.02); 71.0% and 41.2% of the unexposed group achieved ≥ 5% and ≥ 10% weight loss at 12 months, respectively, compared with 63.1% and 31.8% in the exposed group at 12 months (P = 0.04 at 5%; P = 0.02 at 10%).

CONCLUSIONS

Exposure to psychotropic medications was associated with diminished weight loss in patients with medically managed overweight and obesity.

The limits and challenges of antiobesity pharmacotherapy

INTRODUCTION

Pharmacotherapy is a useful adjunct when patients with obesity are unable to achieve adequate benefit from lifestyle interventions.

AREAS COVERED

This review covers the history of antiobesity drugs, efficacy, and risks of currently approved drugs, limits of their usefulness in clinical practice, gaps in knowledge, methodological limitations of clinical trials, and reasons for underutilization.

EXPERT OPINION

In randomized controlled trials, currently approved antiobesity drugs have yielded an average weight loss ranging from approximately 3% to 9% relative to placebo at 1 year. Inadequate inclusion of racial and ethnic minorities and men, and high dropout rates in clinical trials limit generalizability of these findings to clinical practice. Weight loss achieved with antiobesity drugs is generally associated with lowered glycemia, but improvements in blood pressure and lipid measures tend to be marginal. There is limited evidence for sustained weight loss beyond 1 year and for safety and efficacy of antiobesity drugs in children and adolescents, and in post-bariatric surgery patients. None have demonstrated reduction in major adverse cardiovascular events or other significant disease outcomes. Limited health insurance coverage and negative perceptions of physicians have hindered the utilization of antiobesity drugs.

Meta-analysis of placebo group dropout in adult antidepressant trials

BACKGROUND

Minimizing dropouts across antidepressant, placebo-controlled trials remains a major opportunity to improve the efficiency of trials. This meta-analysis investigated placebo dropout rate and its predictors in second generation antidepressant (SGA) for anxiety, depression and obsessive-compulsive disorder (OCD).

METHODS

A random-effects meta-analysis was performed to examine placebo group dropout rate in SGA trials for depression, anxiety and OCD using Freeman - Tukey transformation. Stratified subgroup analysis by diagnostic indication was performed to examine the dropout rate across disorders. Meta-regression was performed to identify correlates between placebo dropout rate and trial and subject characteristics.

RESULTS

Meta-analysis included 148 trials with 18,016 participants receiving placebo. Across antidepressant trials the overall placebo dropout rate was 25% (dropout rate ± standard error (SE) = 0.25 ± 0.01, 95% CI: 0.23-0.27, z = 23.95, p < .001) and was similar across disorders (χ2 = 1.09, df = 2, p = .58). The placebo group dropout rate was 26% in depressive disorders, 25% in anxiety disorders and 22% in OCD. Across all diagnostic indications, earlier publication year, placebo lead-in, studies conducted in a single country (instead of internationally), longer trial duration, fewer study sites, more study visits and less baseline illness severity were associated with higher placebo dropout rate. Significant predictors of placebo dropout did not replicate across disorders.

CONCLUSION

No significant difference was found in placebo dropout rate between internalizing disorders with overall dropout rate for placebo groups in antidepressant trials being around 25%. Placebo dropouts in trials can be minimized by reducing subject burden in trials, enrolling more severely affected subjects and foregoing placebo lead-in periods.

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

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

Effectiveness of a Community-Based Weight Management Program for Patients Taking Antidepressants and/or Antipsychotics

OBJECTIVE

This study aimed to compare weight loss (WL) outcomes for patients taking antidepressants and/or antipsychotics with those not taking psychiatric medication.

METHODS

A total of 17,519 adults enrolled in a lifestyle WL intervention at the Wharton Medical Clinics in Ontario, Canada, were analyzed. Sex-stratified multivariable linear regression analysis was used to examine the association of taking antidepressants, antipsychotics, both, or neither with WL when adjusting for age, initial weight, and treatment time.

RESULTS

Twenty-three percent of patients were taking at least one psychiatric medication. Patients lost a significant amount of weight (P < 0.0001) regardless of psychiatric medication use. Women taking psychiatric medications lost a similar amount of weight as women who were not (P > 0.05). Conversely, men taking antidepressants lost only slightly less weight than men taking both classes or neither class of psychiatric medication (3.2 ± 0.3 kg vs. 5.6 ± 0.9 kg and 4.3 ± 0.1 kg; P < 0.05). However, taking psychiatric medications that cause weight gain was associated with similar significant decreases in weight as taking medications that are weight neutral or associated with WL for both sexes (P > 0.05).

CONCLUSIONS

Results of this study suggest that those who participate in a weight management program can lose significant amounts of weight regardless of psychiatric medication use.

Clinical course of depression symptoms and predictors of enduring depression risk in women with polycystic ovary syndrome: Results of a longitudinal study

OBJECTIVE

To [1] characterize depression symptoms over time and [2] test the hypothesis that adverse metabolic parameters would associate with risk of enduring depression risk in women with polycystic ovary syndrome (PCOS).

DESIGN

Prospective cohort study.

SETTING

University center.

PATIENT(S)

One hundred sixty-three women with PCOS.

INTERVENTION(S)

The Beck Depression Inventory Fast Screen (BDI-FS) was self-administered at baseline and follow-up to identify depression risk, using a cutoff score >4.

MAIN OUTCOME MEASURE(S)

BDI-FS scores.

RESULT(S)

Median baseline age was 29.0 years, and median follow-up interval was 5.5 years. Fifty-nine of 163 women had positive depression screens at baseline (36%); 52 women (32%) screened positive at follow-up. Median change in BDI-II score was 0 (interquartile range, -2, 1) over the study period. Of the 59 women at risk for depression at baseline, 22 screened negative at follow-up (37%), while 37 women remained at risk (63%). Considering these 59 women with positive depression screens at baseline, higher body mass index (BMI) was associated with increased odds of enduring depression risk at follow-up (adjusted odds ratio = 1.09; 95% confidence interval, 1.00, 1.18), in a multivariate logistic regression model. Compared with women with normal body weight at baseline, obese women (BMI >30 kg/m²) had five-fold increased odds of enduring depression risk at follow-up (adjusted odds ratio = 5.07; 95% confidence interval, 1.07, 24.0).

CONCLUSION(S)

The prevalence of depression was relatively stable over time in a cohort of women with PCOS. Elevated BMI is a hallmark of enduring depression risk. These results may assist providers in developing targeted intervention strategies to reduce the prevalence of long-term depressive symptoms in women with PCOS.

Meta-analysis: Risk of dry mouth with second generation antidepressants

OBJECTIVE

The goal of this meta-analysis was to quantify the risk of dry mouth associated with commonly prescribed antidepressant agents and examine the potential implications of medication class, dose, and pharmacodynamics and dose on risk of treatment-induced dry mouth.

DATA SOURCES AND STUDY SELECTION

A PubMed search was conducted to identify double-blind, randomized, placebo-controlled trials examining the efficacy and tolerability of second generation antidepressant medications for adults with depressive disorders, anxiety disorders, and OCD.

DATA EXTRACTION

A random-effects meta-analysis was used to quantify the pooled risk ratio of treatment-emergent dry mouth with second generation antidepressants compared to placebo. Stratified subgroup analysis and meta-regression was utilized to further examine the effects antidepressant agent, class, dosage, indication, and receptor affinity profile on the measured risk of dry mouth.

RESULTS

99 trials involving 20,868 adults. SNRIs (Relative Risk (RR)=2.24, 95% Confidence Interval (CI): 1.95-2.58, z=11.2, p<0.001) were associated with a significantly greater risk of dry mouth (test for subgroup differences χ²=7.6, df=1; p=0.006) compared to placebo than SSRIs (RR=1.65, 95% CI: 1.39-1.95, z=5.8, p<0.001). There was a significant difference found in the risk of dry mouth between diagnostic indications within the SNRI class (test for subgroup differences χ²=9.63, df=1; p=0.002). Anxiety diagnoses (RR=2.78, 95% CI: 2.29-3.38, z=10.32, p<0.001) were associated with a greater risk of dry mouth compared to depression (RR=1.80, 95% CI: 1.48-2.18, z=5.85, p<0.001). Decreased affinity for Alpha-1 (PE=0.18, 95% CI: 0.07-0.28, z=3.26, p=0.001) and Alpha-2 (PE=0.49, 95% CI: 0.22-0.75, z=3.64, p<0.001) receptors and SERT (PE=0.07, 95% CI: 0.01-0.14, z=2.10, p<0.05) was significantly associated with increased risk of dry mouth.

CONCLUSIONS

The current meta-analysis suggests that SSRIs, SNRIs, and atypical antidepressants are all associated with varying degrees of increased risk of dry mouth. SNRIs were associated with a significantly greater risk of dry mouth compared to SSRIs.

Interaction Between Depression, Obesity, and Type 2 Diabetes: A Complex Picture

Depression plays an important role in the pathogenesis and treatment of obesity and type 2 diabetes (T2D). However, its relevance is frequently unrecognized by clinicians and researchers. The purpose of this review is to present a critical analysis of the evidence linking depression and metabolic disorders and to highlight the practical implications of this complex relationship. Evidence obtained from epidemiological, basic, clinical and controlled studies demonstrate that the association goes beyond a random phenomenon. Epidemiological studies have rendered controversial results due to the lack of control of the confounding variables and the bidirectional relationship that exists between the outcomes and the conditions that modulate the association (i.e. socioeconomic status). Animal and human studies have been useful to define the anatomic substrates and physiologic processes that participate in the association, but, the evidence is preliminary in many areas (i.e gene × environmental interactions). Controlled studies have shown the strong impact that treatment of depression has on body weight and the large effect that has the correction of excess body weight on the depression-related symptoms. Practical implications of the depression-obesity duet include the training of the health providers to assess and treat these conditions in a concomitant manner, the need for translational medicine projects and the application the systems biology approach to fill the existing gaps of knowledge.

Current pharmacotherapy for obesity

More than one-third of adults in the USA have obesity, which causes, exacerbates or adversely impacts numerous medical comorbidities, including diabetes mellitus and cardiovascular disease. Despite intensive lifestyle modifications, the disease severity warrants further aggressive intervention, including pharmacotherapy, medical devices and bariatric surgery. Noninvasive anti-obesity drugs have thus now resurfaced as targeted adjunctive therapeutic approaches to intensive lifestyle intervention, bridging the gap between lifestyle and bariatric surgery. In this Review, we discuss FDA-approved anti-obesity drugs in terms of safety and efficacy. As most of these drugs have a mean percentage weight loss reported in clinical trials but individual variations in response rates, a future direction of obesity pharmacotherapy research might include the potential for personalized medicine to target early responders to these anti-obesity drugs.

Pharmacotherapy of Obesity: Clinical Trials to Clinical Practice

PURPOSE OF REVIEW

This review provides an overview of the current state of drug therapy for obesity, with a focus on four new drug therapies-lorcaserin, phentermine/topiramate, naltrexone/bupropion, and liraglutide 3.0 mg-which have been approved by the US Food and Drug Administration (FDA) for long-term management of obesity since 2012. Topics discussed in this paper include rationale for pharmacotherapy, history of antiobesity drugs, and efficacy and safety data from randomized controlled trials with implications for clinical practice.

RECENT FINDINGS

Weight loss achieved by currently approved drugs ranges from approximately 3 to 9%, above and beyond weight loss with lifestyle counseling alone, after a year. Response and attrition rates in clinical trials indicate that the benefits of pharmacotherapy range from substantial for some patients, modest for others, and no benefits for others still. Decisions regarding selection of a suitable drug from the available pharmacotherapy options and duration of treatment should be based on the expected and observed benefit-to-risk balance and tailored to the needs of each individual patient using the principles of shared decision-making.

Method-of-use study of naltrexone sustained release (SR)/bupropion SR on body weight in individuals with obesity

OBJECTIVE

This study assessed the effects of 32 mg naltrexone sustained release (SR)/360 mg bupropion SR (NB) on body weight in adults with obesity, with comprehensive lifestyle intervention (CLI), for 78 weeks.

METHODS

In this phase 3b, randomized, open-label, controlled study, subjects received NB + CLI or usual care (standard diet/exercise advice) for 26 weeks. NB subjects not achieving 5% weight loss at week 16 were discontinued, as indicated by product labeling. After week 26, usual care subjects began NB + CLI. Assessments continued through week 78. The primary end point was percent change in weight from baseline to week 26 in the per protocol population. Other end points included percentage of subjects achieving ≥5%, ≥10%, and ≥15% weight loss, percent change in weight at week 78, and adverse events (AEs) necessitating study medication discontinuation.

RESULTS

NB + CLI subjects lost significantly more weight than usual care subjects at week 26 (8.52% difference; P < 0.0001). Weight loss persisted through 78 weeks. In total, 20.7% of subjects discontinued medication for AEs, including 7.0% for nausea.

CONCLUSIONS

Treatment with NB, used as indicated by prescribing information and with CLI, significantly improved weight loss over usual care alone. NB-facilitated weight loss was sustained for 78 weeks and was deemed safe and well tolerated.

Impulsivity is associated with blood pressure and waist circumference among adolescents with bipolar disorder

OBJECTIVE

Cardiovascular risk factors (CVRFs) and impulsivity are common in bipolar disorder (BD), and CVRFs are also linked with impulsivity through a number of mechanisms, both behavioral and biological. This study examines the association between CVRFs and impulsivity in adolescents with BD.

METHODS

Subjects were 34 adolescents with BD and 35 healthy control (HC) adolescents. CVRFs were based on International Diabetes Federation metabolic syndrome criteria (triglycerides, high-density lipoprotein cholesterol, waist circumference, blood pressure (BP) and glucose). Impulsivity was measured using the computerized Cambridge Gambling Task (CGT). Analyses controlled for age, IQ, lifetime attention deficit hyperactivity disorder, and current antipsychotic use.

RESULTS

Adolescents with BD had higher diastolic BP (73.36 ± 9.57 mmHg vs. 67.91 ± 8.74 mmHg, U = 401.0, p = 0.03), higher triglycerides (1.13 ± 0.60 mmol/L vs. 0.78 ± 0.38 mmol/L, U = 373.5, p = 0.008), and were more likely to meet high-risk criteria for waist circumference (17.6% vs. 2.9%, p = 0.04) vs. HC. Within the BD group, CGT sub-scores were correlated with CVRFs. For example, overall proportion bet was positively correlated with systolic (r = 0.387, p = 0.026) and diastolic (ρ = 0.404, p = 0.020) BP. Quality of decision-making was negatively correlated with systolic BP (ρ = -0.401, p = 0.021) and waist circumference (ρ = -0.534, p = 0.003). Significant interactions were observed, such that BD diagnosis moderates the relationship between both waist circumference and BP with CGT sub-scores.

CONCLUSION

BP and waist circumference are associated with impulsivity in BD adolescents, but not in HC adolescents. Future studies are warranted to determine temporality and to evaluate whether optimizing CVRFs improves impulsivity among BD adolescents.

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.

FDA-Approved Anti-Obesity Drugs in the United States

Obesity is a growing health problem in our society and its treatment has been challenging. In recent decades, several anti-obesity drugs have been withdrawn from the market because of reported and documented adverse effects. After years of interruption, the US Food and Drug Administration (FDA) has recently approved multiple new anti-obesity drugs. The majority of these medications are taken orally, and only one is administered subcutaneously. In this article, we review the efficacy, adverse effects, and mechanism of action of all 5 FDA-approved drugs.

Role of Bupropion Plus Naltrexone for the Management of Obesity

Objective. The pharmacology, pharmacokinetics, efficacy, and safety of bupropion plus naltrexone for weight loss were reviewed. Data Sources. A MEDLINE search (1970 to November 2015) was conducted for English-language articles using specific MESH terms. Study Selection and Data Extraction. Published Phase 3 clinical trials with primary endpoints related to weight loss were included and critiqued in this review. Study Selection and Data Extraction. Five trials were retrieved and reviewed regarding the efficacy and safety of bupropion plus naltrexone among obese and overweight patients. Data Synthesis. Bupropion is a dopamine/norepinephrine reuptake inhibitor, and naltrexone is an opioid receptor antagonist. The combination of these agents has led to increased weight loss, compared to placebo, among overweight and obese patients with a body mass index (BMI) at or above 30 or BMI at or above 27 with a comorbid condition. The combination of bupropion and naltrexone can produce an average placebo-subtracted weight loss of 4.25% over 56 weeks. Gastrointestinal (ie, nausea, vomiting, constipation) and central nervous system adverse events (ie, headache, dizziness) were commonly reported, and there was a high dropout rate among participants. Conclusions. Bupropion plus naltrexone has demonstrated effective weight loss, in conjunction with lifestyle modifications, among overweight and obese patients with and without comorbidities. Bupropion plus naltrexone has not been studied among special patient populations, such as those with sleep apnea, osteoarthritis, or extreme BMIs. Additional clinical trials and postmarketing data will provide a better understanding of this medication for weight loss.

Long-Term Weight Change after Initiating Second-Generation Antidepressants

(1) Objective: To examine the relationship between the choice of second-generation antidepressant drug treatment and long-term weight change; (2) Methods: We conducted a retrospective cohort study to investigate the relationship between choice of antidepressant medication and weight change at two years among adult patients with a new antidepressant treatment episode between January, 2006 and October, 2009 in a large health system in Washington State. Medication use, encounters, diagnoses, height, and weight were collected from electronic databases. We modeled change in weight and BMI at two years after initiation of treatment using inverse probability weighted linear regression models that adjusted for potential confounders. Fluoxetine was the reference treatment; (3) Results: In intent-to-treat analyses, non-smokers who initiated bupropion treatment on average lost 7.1 lbs compared to fluoxetine users who were non-smokers (95% CI: −11.3, −2.8; p-value < 0.01); smokers who initiated bupropion treatment gained on average 2.2 lbs compared to fluoxetine users who were smokers (95% CI: −2.3, 6.8; p-value = 0.33). Changes in weight associated with all other antidepressant medications were not significantly different than fluoxetine, except for sertraline users, who gained an average of 5.9 lbs compared to fluoxetine users (95% CI: 0.8, 10.9; p-value = 0.02); (4) Conclusion: Antidepressant drug therapy is significantly associated with long-term weight change at two years. Bupropion may be considered as the first-line drug of choice for overweight and obese patients unless there are other existing contraindications.

Comparative Effectiveness of Smoking Cessation Medications to Attenuate Weight Gain Following Cessation

OBJECTIVE

To compare the postcessation weight gain following the use of different FDA-approved smoking cessation medications among obese smokers.

METHODS

A retrospective cohort study was conducted using the General Electric (GE) electronic medical record database (2006-2011). The cohort consisted of obese adult smokers newly initiating use of an FDA-approved smoking cessation medication (i.e., bupropion vs. varenicline). The outcome variable was weight change at 3, 6, or 12 months following the first prescription. Descriptive analyses and t-tests were conducted to assess the frequency distribution of sample characteristics and their association with the postcessation weight change. Multivariate linear regression models were carried out to compare the weight change among the FDA-approved smoking cessation medications and to identify predictors of weight change at 3, 6, and 12 months after assessing the model assumptions.

RESULTS

The mean weight gain was 1.14 pounds (±17.26), 2.06 pounds (±18.46), and 3.06 pounds (±20.78) at 3-, 6-, and 12-month, respectively. Obese smokers who were prescribed varenicline had a mean weight gain of 1.18 pounds (±16.75), 2.14 pounds (±18.14), and 3.12 pounds (±20.89) for each follow up, while those who were prescribed bupropion had a mean weight gain of 0.23 pounds (±25.90), 0.22 pounds (±25.32), and 1.47 pounds (±17.50), respectively. Descriptive analysis showed that obese smokers taking bupropion had less weight gain than those taking varenicline at each follow up; however, this association was not statistically significant after accounting for all covariates.

CONCLUSIONS

While patients using bupropion gained slightly less weight compared to those using varenicline, type of smoking cessation medication was not a significant predictor of weight change in the multivariate linear regression model.

Naltrexone HCI/bupropion HCI for chronic weight management in obese adults: patient selection and perspectives

Naltrexone, an opiate antagonist, and bupropion, a noradrenergic/dopaminergic antidepressant, have many effects on the reward systems of the brain. These medications impact eating behavior, presumably via their impact on food reward. However, only bupropion induces weight loss in obese individuals, while naltrexone does not have any appreciable effect. The combination of 32 mg of naltrexone and 360 mg of bupropion in a sustained-release combination pill form has been recently approved for obesity treatment. Studies have shown that the combination of these two medications is more effective in inducing weight loss, when combined with lifestyle intervention and calorie reduction, than each individual medicine alone. The naltrexone-bupropion combination, when combined with lifestyle intervention and modest calorie reduction, seems to be quite effective for 6-month and 1-year outcomes for clinically significant weight loss (over 5% of total body weight). These medications are not devoid of serious side effects, however, and careful patient selection can reduce dramatic complications and increase positive outcomes. This paper reviews existing weight loss clinical trials with bupropion and the bupropion-naltrexone combination. Additionally, the rationale for the suggested patient selection and clinical strategies for special patient populations are discussed.

Diabetes-associated depression: the serotonergic system as a novel multifunctional target

Diabetes associated depression is a largely understudied field which nonetheless carries a significant disease burden. The very low therapeutic efficacy of the existing conventional drugs with poor outcome may be, in part, due to uncertainty of the mechanism involved that clearly explains the existing comorbidity. The main purpose of this review was to address the sophisticated mechanisms of this comorbidity with a view of developing potential novel targets with higher efficacy and specificity. Data were collected from database searches including PubMed, references from relevant English language research/review articles and other official publications. Articles from 1990 to 2013 were included, and a broad search term criteria were followed for data mining so that relevant information was not missed out. Some of the search terms used included; diabetes-induced depression, diabetes and serotonin, hypothalamic-pituitary-adrenal (HPA) axis and diabetes and glucocorticoids in diabetes. Neuropathologically, depletion of brain monoaminergic activity specifically the serotonin (5-hydroxytryptamine [5-HT]) system, due to chronically persisting diabetic state may lead to the mood and behavioral complications that further add on worsening the quality life years. The 5-HT system through multifunctional tasks regulates neurogenesis and plasticity and by complex receptor mechanism controls the emotional and behavioral activity. Persisting hyperglycemia leads to impaired neurogenesis, decreased synaptic plasticity, undesired neuro-anatomical alterations, neurochemical deficits, and reduced neurotransmitter activity. The neurotrophic factors and secondary messenger functions affected at molecular and genetic levels indicate the impact of diabetes-mediated dysregulation on neuronal circuits. HPA activity, glycogen synthase kinase 3, and insulin signaling controls were also found to be hampered, interlinked to 5-HT system following diabetic progression.

Pharmacotherapy of binge-eating disorder: a review

OBJECTIVES

The purpose of this article is to provide a comprehensive review of pharmacotherapy for binge eating disorder, including new therapeutic approaches such as centrally acting sympathomimetics, nootropics, lisdexamfetamine, and substance abuse treatment agents such as acamprosate, sodium oxybate, baclofen, and naltrexone.

METHODS

The study was conducted by searching the MEDLINE database using the keywords "binge eating disorder," "obesity," and "pharmacological therapy."All available studies on each drug dating from 1988 to the present were considered, focusing mainly on randomized controlled trials (RCTs). Other types of studies were considered when no RCTs were found. We drafted separate tables for open-label studies (), RCT (), and retrospective studies (). Each study is detailed by the number of subjects, additional design considerations, doses, results, additional main comparators, and study limitations.

RESULTS

The data emerging from this study seem to show that, at least in the short term, some specific medications within the classes of antidepressants, anticonvulsants, and antiobesity agents may prove promising in achieving the main objectives in the treatment of binge eating disorder: reducing the frequency of binge eating, reducing weight, and improving the associated psychopathology. The major limitation in interpreting these results is the short duration of the studies and the lack of adequately sized trials, or trials including patients with medical comorbidities.Good results are being obtained with new combinations of drugs and with substance abuse treatment agents. Although the precise nature of the relationship between substance use disorders and binge eating disorder remains to be clarified, the evidence suggests that treatments recognized as effective for substance use disorders may be useful as novel treatments for binge eating disorder. This field of research remains open to future studies with more precise methodological approaches and more detailed parameter assessment; a multidisciplinary approach is also essential to better understand such a complex disease.

Bupropion-SR plus naltrexone-SR for the treatment of mild-to-moderate obesity

Naltrexone-bupropion is a recently approved drug combination for chronic weight management. In this article, we discuss the rationale for its use as a combination followed by a comprehensive review of safety and efficacy data from major preclinical, phase II and III clinical trials.

Superstition predicts favorable weight change in an open-placebo trial: a prospective study

Given the difficulty of losing weight via adhering to healthy lifestyle choices, this study sought to understand how a placebo may elicit favorable weight change. Specifically, we examined if superstition may be related to increased responsiveness to an open-placebo. In this pilot study of 25 undergraduate participants, it was hypothesized that individuals with higher levels of superstition may be more responsive to a 3-week open-placebo weight change trial. Participants were given once-daily saltine crackers to use as open-placebos for weight change in their preferred direction (gain or loss). The weight of each participant was measured before and after the 3-week open-placebo period. A Pearson's r correlation showed a significant positive relationship between superstition and placebo responsiveness, determined by weight gain or loss in the preferred direction, r (25) = 0.493, p < 0.05. We hope these preliminary results engender future research on open-placebo uses for weight management.

Effect of comedication of bupropion and other antidepressants on body mass index

BACKGROUND

Weight gain as an adverse effect of monotherapy of antidepressant has been well-studied. The effects of augmentation therapy involving multiple antidepressants, on weight changes needs to be adequately addressed.

OBJECTIVE

To study the co-medication effects of bupropion in combination with six individual antidepressants on body mass index (BMI) using EMR based data analysis.

METHODS

Allscripts data warehouse was used to identify patients on monotherapy of five selective serotonin reuptake inhibitor (SSRI) drugs, escitalopram, sertraline, citalopram, paroxetine, fluoxetine, one selective norepinephrine reuptake inhibitor (SNRI) duloxetine and the aminoketone, bupropion for at least 180 days. We also identified patients on co-medication of SSRI/SNRI drugs with bupropion. Six ANCOVA models were built to compare the short term effects on BMI, among monotherapy and co-medication groups. The patients' clinical conditions and demographics were included to account for confounding effects.

RESULTS

Monotherapy of all the SSRI/SNRI drugs showed significant weight increase, consistent with that of previous studies. The co-medication of bupropion and escitalopram showed a significantly higher increase in BMI than monotherapy (P = 0.0102). The increase in BMI in the other five co-medication groups was not significantly different from their respective monotherapy groups.

CONCLUSION

Our study reports an adverse weight gain on co-medication of escitalopram and bupropion, which warrants further validation studies. Considering co-medication effects of antidepressants on weight is important to design robust depression treatment plans.

Pharmacological Management of the Obese Patient

Being obese goes beyond moral failure or a character flaw. Obesity has the defining characteristics of a chronic disease for which there is no cure. Treatment may require lifelong treatment which may include pharmacotherapy. Experience with long term use of obesity drugs is limited but evidence suggests that pharmacotherapy can improve patient outcomes and patient outlook. With current obesity drugs, weight loss is usually modest but clinically significant satisfying the FDA threshold for drug effectiveness. This weight loss is associated with clinically significant improvements in many obesity co morbidities and risk factors and could eliminate some risk factors with continued use. When used in conjunction with a comprehensive program for weight management, obesity drugs can reduce appetite or hunger, increase satiety, provide improved control over aberrant eating behaviors and modify food seeking behaviors. Pharmacotherapy can enhance weight loss and compliance during the periods of weight loss and in maintaining that weight loss, increasing physical activity and may enhance a focus on making life long changes.

This article will discuss mechanisms of action of obesity drugs, theories of altered body defense of body weight, Food and Drug Administration (FDA) approved obesity drugs, and off-label use of FDA approved drugs. The value of over-the counter (OTC) medications and diet supplements, as well as fat substitutes in the treatment of obesity drugs will be explored. Obesity drugs awaiting FDA approval and compounds under development will be reviewed. The section on approaches to drug management will include clinical considerations for; who should receive pharmacotherapy and when, length of treatment and drug discontinuation, weight regain and the role of pharmacotherapy.

Drug treatment of obesity: current status and future prospects

Obesity is a growing epidemic and a major contributor to the global burden of disease. Obesity strains the healthcare systems and has profound economic and psychosocial consequences. Historically, pharmacotherapy for obesity has witnessed the rise and fall of several promising drug candidates that had to be eventually withdrawn due to unacceptable safety concerns. Currently four drugs are approved for chronic weight management in obese adults: orlistat, lorcaserin, phentermine/topiramate extended release and naltrexone/bupropion extended release. While lorcaserin and phentermine/topiramate were approved by US Food and Drug Administration (FDA) in 2012, after a gap of 13 years following the licensing of orlistat, naltrexone/bupropion has been recently approved in 2014. This review provides a brief overview of these current therapeutic interventions available for management of obesity along with the evidence of their safety and efficacy. Additionally, several novel monotherapies as well as combination products are undergoing evaluation in various stages of clinical development. These therapies if proven successful will strengthen the existing armamentarium of antiobesity drugs and will be critical to combat the global public health crisis of obesity and its associated co-morbidities.

Drug safety evaluation of naltrexone/bupropion for the treatment of obesity

INTRODUCTION

Obesity is a known health risk for the development of several preventable diseases. Obesity-related metabolic alterations negatively impact different physiological mechanisms, which supports the rationale for the use of combined drug therapy. Naltrexone is an opioid antagonist for the treatment of opioid and alcohol dependency, whereas bupropion is a norepinephrine/dopamine reuptake inhibitor used to treat depression and smoking cessation. Although not effective as individual monotherapies for obesity, naltrexone and bupropion in combination produce weight loss and a metabolic profile beneficial for the potential treatment of obesity.

AREAS COVERED

This review examines the safety and antiobesity effects of naltrexone and bupropion alone and in combination. It reviews the results of four Phase III clinical trials of a novel fixed dose of sustained-released naltrexone/bupropion.

EXPERT OPINION

Naltrexone/bupropion has a greater weight loss efficacy than two FDA-approved medications, orlistat and lorcaserin. Although the weight loss produced by phentermine/topiramate is superior to naltrexone/bupropion, the safety profile of naltrexone/bupropion has less severe adverse effects. In addition, naltrexone/bupropion is well tolerated, with nausea being the most reported adverse event. Unlike other centrally acting medications, lorcaserin and phentermine/topiramate, naltrexone/bupropion has no abuse potential.

Naltrexone/bupropion for obesity: an investigational combination pharmacotherapy for weight loss

The mechanism of action of the combination therapy, naltrexone/bupropion (NB), for obesity has not been fully described to date. Weight loss attempts rarely result in long-term success. This is likely a result of complex interactions among multiple peripheral and CNS systems that defend against weight loss, and may explain the overwhelming lack of effective obesity treatments. NB is an investigational combination therapy for obesity that was developed based on evidence that obesity involves alterations in the hypothalamic melanocortin system as well as brain reward systems that influence food craving and mood. Naltrexone and bupropion both have actions in these brain regions that may cause them to influence food intake, food craving, and other aspects of eating behavior that affect body weight. We review the individual actions of naltrexone and bupropion in brain hypothalamic and reward systems, and describe the current in vitro, in vivo, and clinical evidence for how NB influences food intake and produces weight loss.

"Meaningful use" provides a meaningful opportunity

A model is described for meeting the mandate that includes implementation of a comprehensive smoking (tobacco) cessation program for cancer patients as an alternative to the minimal intervention approach. The importance of an institution‐wide, automated system to identify and refer tobacco users to treatment is discussed within the context of implementing the meaningful use regulations for electronic health records.

The overlap between binge eating disorder and substance use disorders: Diagnosis and neurobiology

BACKGROUND AND AIMS

Binge eating disorder (BED) is a relatively common condition, especially in young adult females, and is characterized by chronic over-consumption of food resulting in embarrassment, distress, and potential health problems. It is formally included as a disorder in DSM-5 for the first time, an acknowledgement to its debilitating nature. This article explores the overlap between binge eating disorder and substance use disorders (SUD).

METHODS

The bibliographic search was a computerized screen of PubMed databases from January 1990 to the present. Binge eating disorder, substance use disorder, binging, obesity, food addiction, comorbidity, dopamine, opioid, serotonin, glutamate, and pharmacological treatment were the keywords used in searching.

RESULTS

BED shares similar phenomenology to SUD, including significant urges to engage in binging episodes, resulting in distress and impairment. Similar neurobiological pathways are found in both BED and SUD and medications based on similar neurobiology have been examined for both disorders. A subset of individuals with BED may have a "food addiction", but there is no clinical agreement on the meaning of "food addiction". Exploring the relationship between BED and obesity may also shed light on the extent to which BED can be viewed as an addiction.

CONCLUSIONS

Overall, nascent research regarding BED and SUD suggests an overlap between these disorders, but there are discrepancies between these two disorders that need further exploration.

Acute behavioural effects of bupropion and naltrexone, alone and in combination, in non-deprived male rats presented with palatable mash

RATIONALE

In appetite research, drugs frequently progress to clinical trials on the basis of outcome (reduced food intake/body weight gain) with insufficient attention to process (behavioural analysis). Although bupropion and naltrexone (alone and in combination) reduce food consumption in rodents and humans, their effects on behaviour during feeding tests have not been thoroughly investigated.

OBJECTIVES

This study aimed to assess the behavioural specificity of anorectic responses to bupropion, naltrexone and their combination.

METHODS

Video analysis was employed to characterise the behavioural effects of acute systemic treatment with bupropion (10.0-40.0 mg/kg), naltrexone (0.1-3.0 mg/kg) and combined bupropion (20 mg/kg) plus naltrexone (0.1-1.0 mg/kg) in non-deprived male rats exposed for 1 h to palatable mash. Particular attention was paid to the behavioural satiety sequence (BSS).

RESULTS

In experiment 1, the anorectic response to 40 mg/kg bupropion was associated with significant psychomotor stimulation and a complete disruption of the BSS. In experiment 2, the anorectic response to 3 mg/kg naltrexone was associated with an accelerated but otherwise normal BSS. In experiment 3, the co-administration of 20 mg/kg bupropion and naltrexone (0.1 and 1.0 mg/kg) not only produced an additive anorectic profile (including a reduced rate of eating), but the addition of the opioid receptor antagonist also concurrently attenuated the psychomotor stimulant response to the atypical antidepressant.

CONCLUSIONS

Low-dose co-treatment with naltrexone and bupropion produces a stronger suppression of appetite than that seen with either agent alone and has the additional advantage of reducing some of the unwanted effects of bupropion.