Phentermine-topiramate: First combination drug for obesity

Charting New Territories in Obesity Management- Traditional Techniques to Tirzepatide

BACKGROUND

Obesity, a pervasive global health challenge affecting more than 2 billion people, requires comprehensive interventions. Traditional approaches, including lifestyle modification, and diverse drugs targeting a gastrointestinal hormone, including glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 (Liraglutide, Semaglutide, Exenatide, Albiglutide, Dulaglutide, Lixisenatide, Orlistat, Phentermine/Topiramate, Lorcaserin, Sibutramine, and Rimonabant) offer tailored strategies; yet their effectiveness is limited and some drugs were taken off the market. Moreover, various surgical modalities, such as Roux-en-Y Bypass surgery, sleeve gastrectomy, intragastric balloons, biliopancreatic diversion with duodenal switch, laparoscopic adjustable gastric band, and vagal nerve blockade can be considered but are associated with numerous side effects and require careful monitoring. Consequently, there is a pressing need for novel anti-obesity treatments.

METHODS

This comprehensive review was based on the available data to discuss the traditional pharmaceutical and surgical therapeutical strategies for obesity, going further to discuss tirzepatide's mode of action, its outcomes for obesity, and the associated side effects.

RESULTS

In this landscape, tirzepatide, initially designed for type 2 diabetes management, emerges as a potential game-changer. Functioning as a dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist, it not only addresses control but also introduces a fresh perspective on weight reduction. This review intricately explores tirzepatide's mechanism, dissecting insights from clinical studies and positioning it as a major force in obesity treatment.

CONCLUSIONS

In the middle of significant shifts in obesity management, tirzepatide presents itself as a promising and cost-effective intervention. Its Food and Drug Administration approval marks a milestone in the realm of obesity therapeutics. Going beyond a recapitulation of findings, the conclusion emphasizes the imperative for ongoing exploration and vigilant safety monitoring in tirzepatide's application.

Multifactorial Basis and Therapeutic Strategies in Metabolism-Related Diseases

Throughout the 20th and 21st centuries, the incidence of non-communicable diseases (NCDs), also known as chronic diseases, has been increasing worldwide. Changes in dietary and physical activity patterns, along with genetic conditions, are the main factors that modulate the metabolism of individuals, leading to the development of NCDs. Obesity, diabetes, metabolic associated fatty liver disease (MAFLD), and cardiovascular diseases (CVDs) are classified in this group of chronic diseases. Therefore, understanding the underlying molecular mechanisms of these diseases leads us to develop more accurate and effective treatments to reduce or mitigate their prevalence in the population. Given the global relevance of NCDs and ongoing research progress, this article reviews the current understanding about NCDs and their related risk factors, with a focus on obesity, diabetes, MAFLD, and CVDs, summarizing the knowledge about their pathophysiology and highlighting the currently available and emerging therapeutic strategies, especially pharmacological interventions. All of these diseases play an important role in the contamination by the SARS-CoV-2 virus, as well as in the progression and severity of the symptoms of the coronavirus disease 2019 (COVID-19). Therefore, we briefly explore the relationship between NCDs and COVID-19.

Simultaneous determination of barbiturates, phenytoin and topiramate in hair by LC-MS/MS and application to real samples

INTRODUCTION

Hair analysis is useful for monitoring exposure to drugs such as antiepileptics owing to long-term therapy and a high possibility of abuse of drugs, which could be fatal. An effective and rapid analytical method for the simultaneous determination of six barbiturates, as well as phenytoin and topiramate in hair samples was developed and validated by liquid-chromatography-tandem mass spectrometry (LC-MS/MS).

METHODS

Three different extraction methods were investigated for the development of an appropriate analytical method. Hair was finely cut and then extracted with methanol, methanol containing 1% hydrochloric acid, and liquid-liquid extraction in acidic condition.

RESULTS

There was no significant difference in the matrix effects among these three methods. Recoveries clearly declined in the extraction involving both acidic methanol extraction and a LLE in acidic condition. Methanol incubation was chosen as the appropriate extraction method with acceptable matrix effects and recoveries. After validating the methanol incubation, the limit of detection (LOD) and limit of quantification (LOQ) were determined as 0.01 and 0.02 ng/mg for topiramate and 0.25-0.5 and 0.5-1 ng/mg for the others in hair. The LC-MS/MS method was precise and accurate with a dynamic linear range of 0.02-5 ng/mg for topiramate and 0.5 or 1-50 ng/mg for others. This method was applied to authentic hair samples of two drug users. The hair concentrations of phenobarbital were 0.2-17.1 ng/mg in segmental analysis in one female subject and those of topiramate were 0.19-0.93 ng/mg in another female subject.

DISCUSSION

The quantitative method was developed to determine 8 antiepileptics using LC-MS/MS. This method performed hair segmental analysis to provide useful informative and chronological data in both of the forensic and clinical toxicology fields.

Neurochemical regulators of food behavior for pharmacological treatment of obesity: current status and future prospects

In recent decades, obesity has become a pandemic disease and appears to be an ultimate medical and social problem. Existing antiobesity drugs show low efficiency and a wide variety of side effects. In this review, we discuss possible mechanisms underlying brain-gut-adipose tissue axis, as well as molecular biochemical characteristics of various neurochemical regulators of body weight and appetite. Multiple brain regions are responsible for eating behavior, hedonic eating and food addiction. The existing pharmacological targets for treatment of obesity were reviewed as well.

The risk of cardiovascular complications with current obesity drugs

INTRODUCTION

Obesity is associated with an increased risk of cardiovascular morbidity and mortality. Four medications are approved by the US Food and Drug Administration (FDA) for chronic weight management when used as an adjunct to a reduced-calorie diet and increased physical activity in adults. These medications result in clinically significant weight losses, as well as improvements in some cardiometabolic risk factors.

AREAS COVERED

We briefly review the history of anti-obesity medications (AOMs) as related to cardiovascular safety, and summarize weight loss efficacy and cardiovascular data from clinical trials of orlistat, phentermine/topiramate, naltrexone/bupropion, and liraglutide.

EXPERT OPINION

Current AOMs approved for chronic weight management have generally favorable effects on some cardiometabolic parameters. However, the long-term safety of orlistat, phentermine/topiramate, and naltrexone/bupropion on cardiovascular morbidity and mortality have not been established. The cardiovascular safety of liraglutide, at a dose of 1.8 mg/d, was demonstrated in a large randomized outcomes trial in participants with type 2 diabetes.

An evaluation of liraglutide including its efficacy and safety for the treatment of obesity

Introduction: The prevalence of obesity is increasing worldwide and associated conditions, particularly type 2 diabetes mellitus (T2DM), also show increasing prevalence. Lifestyle intervention should be the first line of management for obesity but additional pharmacotherapy is often required and bariatric surgery is appropriate in more severe cases. Drugs acting as glucagon-like peptide-1 receptor agonists (GLP-1RAs) developed for the management of T2DM reduce body weight and liraglutide is the first GLP-1RA to be approved for the treatment of obesity in patients with and without T2DM.Areas covered: In this review of relevant published material, the authors summarize the pharmacokinetics, pharmacodynamics, clinical efficacy and safety of liraglutide for the treatment of obesity.Expert opinion: Liraglutide effectively reduces body weight and body fat through mechanisms involving reduced appetite and lowered energy intake, independent of its glucose-lowering effects. Like most of the other medications currently available for obesity, liraglutide has some common adverse effects, although generally not serious ones. Liraglutide has additional benefits in reducing cardiovascular events in patients with T2DM but the cost and the need for daily injections may limit its use in obesity. Newer GLP-1RAs, such as semaglutide, or other drugs in development for obesity may have advantages over liraglutide.

Pharmacologic therapy of obesity: mechanisms of action and cardiometabolic effects

Obesity is a chronic, relapsing, multifactorial disease, which has become a serious threat to public health globally, as the worldwide prevalence of obesity increases exponentially over time. It has been well established that obesity is associated with multiple adverse cardiometabolic effects. Although lifestyle changes are the first line of therapy for obesity, these are often insufficient in attaining weight loss goals. Orlistat, phentermine/topiramate, lorcaserin, naltrexone/bupropion, and liraglutide are agents that have been approved for the treatment of obesity but their effects on cardiometabolic risk factors and outcomes have not been clearly elucidated. Given the detrimental repercussions of obesity on cardiometabolic health, there is a pressing clinical need to fully understand the effects of these agents beyond weight loss alone. Certain previous weight loss drugs have been withdrawn due to safety concerns and this underlines the need for more careful assessment of the effects of the various pharmacologic agents currently used for the treatment of obesity. This review aims to provide an overview of the mechanisms, efficacy, safety and cardiometabolic effects of the currently available pharmacologic agents for weight loss.

Utilisation of the Prestwick Chemical Library to identify drugs that inhibit the growth of mycobacteria

Tuberculosis (TB) is an infectious bacterial disease that kills approximately 1.3 million people every year. Despite global efforts to reduce both the incidence and mortality associated with TB, the emergence of drug resistant strains has slowed any progress made towards combating the spread of this deadly disease. The current TB drug regimen is inadequate, takes months to complete and poses significant challenges when administering to patients suffering from drug resistant TB. New treatments that are faster, simpler and more affordable are urgently required. Arguably, a good strategy to discover new drugs is to start with an old drug. Here, we have screened a library of 1200 FDA approved drugs from the Prestwick Chemical library using a GFP microplate assay. Drugs were screened against GFP expressing strains of Mycobacterium smegmatis and Mycobacterium bovis BCG as surrogates for Mycobacterium tuberculosis, the causative agent of TB in humans. We identified several classes of drugs that displayed antimycobacterial activity against both M. smegmatis and BCG, however each organism also displayed some selectivity towards certain drug classes. Variant analysis of whole genomes sequenced for resistant mutants raised to florfenicol, vanoxerine and pentamidine highlight new pathways that could be exploited in drug repurposing programmes.

Investigational glucagon-like peptide-1 agonists for the treatment of obesity

INTRODUCTION

Obesity is a worldwide problem predisposing to type 2 diabetes mellitus (T2DM), hypertension, cardiovascular disease, cancer and other comorbidities. Lifestyle modification is the first line intervention but adjunctive pharmacotherapy is often required. The GLP-1 receptor agonists (GLP-1RAs) were developed primarily for T2DM and they also reduce body weight. Liraglutide was approved for the treatment of obesity and other GLP-1RAs are likely to be suitable for this indication.

AREAS COVERED

This review describes the GLP-1RAs that have been approved for the treatment of T2DM as potential candidates for the treatment of obesity and the new agents currently under development which may have advantages in patient adherence.

EXPERT OPINION

The GLP-1RAs offer a welcome addition to obesity pharmacotherapy. They appear to be free of serious adverse effects although uncertainty remains about possible risks of pancreatitis and neoplasms. However, they have frequent gastrointestinal side effects, particularly nausea, which limits their tolerability. Cardiovascular outcome studies in T2DM support their use and this is likely to increase in both T2DM and obesity. Other GLP-1RAs which can be given by subcutaneous injection once weekly or less frequently or by oral administration would have advantages especially if nausea is less frequent than with liraglutide.

Topiramate-Induced Persistent Eyelid Myokymia

Background. Topiramate (TPM) is a psychotropic drug, which is used mainly as an antiepileptic drug and now over the years is used for a wider range of indications, including migraine prophylaxis and binge eating disorders. Although ocular side effects of Topiramate have been frequently reported, neuroophthalmologic manifestations such as myokymia are rarely reported. Case Presentation. This case report presents a case of a 47-year-old woman who had begun TPM for binge eating problem. She developed unilateral long standing lower eyelid twitching, which progressed to upper eyelid and eyebrow at the same side. The patient was not a smoker or excessive alcohol or caffeine abuser. Increasing the resting time and changing life style made no significant changes in her eyelid twitching. There was no definite evidence by neuroimaging and clinical or laboratory evaluations causing eyelid myokymia. The symptoms resolved with discontinuation of TPM. Conclusion. Although eyelid myokymia is a benign and self-limited condition, it sometimes becomes a source of distress in chronic long standing cases. Physicians should be aware of the neuroophthalmologic side effects of this drug.

Topiramate as a rare cause of reversible Fanconi syndrome and acute kidney injury: a case report and literature review

Topiramate (TPM) is a sulfa-derivative monosaccharide that has been used for multiple indications in the last several years. We describe a 53-year-old woman with known chronic kidney disease stage 2 and baseline creatinine of 1 mg/dL who developed acute kidney injury and proximal renal tubular dysfunction while on TPM for depression. The Naranjo Adverse Drug Reaction Probability Scale indicated a probable relationship (score of 6) between TPM and acute kidney injury as well as proximal tubular dysfunction; these renal conditions resolved on withdrawal of TPM. To our knowledge, this is the first report of such a scenario. Patients receiving TPM therapy should be closely monitored for evidence of kidney dysfunction and electrolyte abnormalities.

European Guidelines for Obesity Management in Adults

Obesity is a chronic metabolic disease characterised by an increase of body fat stores. It is a gateway to ill health, and it has become one of the leading causes of disability and death, affecting not only adults but also children and adolescents worldwide. In clinical practice, the body fatness is estimated by BMI, and the accumulation of intra-abdominal fat (marker for higher metabolic and cardiovascular disease risk) can be assessed by waist circumference. Complex interactions between biological, behavioural, social and environmental factors are involved in regulation of energy balance and fat stores. A comprehensive history, physical examination and laboratory assessment relevant to the patient's obesity should be obtained. Appropriate goals of weight management emphasise realistic weight loss to achieve a reduction in health risks and should include promotion of weight loss, maintenance and prevention of weight regain. Management of co-morbidities and improving quality of life of obese patients are also included in treatment aims. Balanced hypocaloric diets result in clinically meaningful weight loss regardless of which macronutrients they emphasise. Aerobic training is the optimal mode of exercise for reducing fat mass while a programme including resistance training is needed for increasing lean mass in middle-aged and overweight/obese individuals. Cognitive behavioural therapy directly addresses behaviours that require change for successful weight loss and weight loss maintenance. Pharmacotherapy can help patients to maintain compliance and ameliorate obesity-related health risks. Surgery is the most effective treatment for morbid obesity in terms of long-term weight loss. A comprehensive obesity management can only be accomplished by a multidisciplinary obesity management team. We conclude that physicians have a responsibility to recognise obesity as a disease and help obese patients with appropriate prevention and treatment. Treatment should be based on good clinical care, and evidence-based interventions; should focus on realistic goals and lifelong multidisciplinary management.

Anti-obesity drugs

PURPOSE OF REVIEW

The prevalence of obesity across the world continues to climb, bringing with it otherwise preventable obesity-related comorbidities including type 2 diabetes, hypertension and cardiovascular disease. Weight loss is difficult to achieve and maintain through lifestyle interventions alone, leading to intense efforts to develop adjunctive pharmacological approaches. Herein, we examine recent advances in this field and limitations of currently available and emerging agents.

RECENT FINDINGS

Liraglutide, lorcaserin and combination of phentermine-topiramate and bupropion-naltrexone have all been the subject of recent studies examining their efficacy as weight-loss agents. Although each effectively induces weight loss over and above placebo, significant concerns exist regarding side-effect profiles and safety, along with their ability to achieve sustained effects. Dropout rates in all examined studies were up to 50% or more, usually a result of intolerable side-effects. Recruitment of a high proportion of women of European descent also casts doubt on the generalizability of trial data.

SUMMARY

Pharmacological interventions for weight loss remain limited, with side-effects often outweighing efficacy. Interestingly, substantial early weight loss was associated with sustained loss, suggesting a responsive phenotype and future trials might best be targeted in identifying responsive subpopulations.