Valvular abnormalities and cardiovascular status following exposure to dexfenfluramine or phentermine/fenfluramine

Efficacy of pharmacological treatments for Dravet syndrome: Systematic review and network meta-analysis

BACKGROUND

Numerous anti-seizure medications (ASMs) have been developed to treat Dravet syndrome (DS). This network meta-analysis aimed to comprehensively analyse the efficacy of ASMs in DS patients, especially in non-seizure-free patients after treatment.

METHODS

PubMed, EMBASE, Cochrane Library, and Chinese National Knowledge Infrastructure databases were searched. The treatment efficacy was assessed by the percentage reduction in monthly convulsive seizure frequency (MCSF) from baseline or individuals who achieved at least a 50 % or 75 % reduction from baseline in convulsive seizure frequency (CSF).

RESULTS

Six randomised controlled trials with 633 participants and seven regimens based on four add-on ASMs-fenfluramine (FFA), stiripentol (STP), cannabidiol (CBD), and soticlestat-were included. All drug regimens were superior to the placebo at achieving at least 50 % and 75 % reductions in CSF, but only STP, 0.4 mg/kg/d FFA (FFA0.4), and 0.7 mg/kg/d FFA (FFA0.7) reduced MCSF. STP (50 mg/kg/d) had the highest correlation with reducing MCSF and achieving at least a 50 % reduction from baseline in CSF, followed by FFA0.4 and FFA0.7. Soticlestat and CBD may also be effective in reducing seizures in DS patients.

CONCLUSION

STP can be recommended as the first choice among the included drug regimens for reducing seizures in DS patients, while FFA0.4 may be considered the second choice. Other drug regimens can be used as alternative treatments. STP, FFA0.4, and FFA0.7 may consistently present favourable efficacy in most DS patients, while other regimens may present prominent inter-individual variability. Appropriate dose selection and intense monitoring are necessary when treating DS using these drugs.

Benfluorex metabolism complemented by electrochemistry-mass spectrometry

The hypolipidemic and hypoglycemic drug benfluorex was widely applied to treat type 2 diabetes mellitus and metabolic syndrome in overweight patients since 1976. However, benfluorex was connected to multiple cases of valvular heart disease and pulmonary arterial hypertension later on. Similar adverse drug reactions were previously found to be associated to the structurally related drug fenfluramine, which was attributed to the formation of its N-deethylated metabolite norfenfluramine. Even though norfenfluramine was known to be a common metabolite of fenfluramine and benfluorex, only fenfluramine was withdrawn from European and United States markets in 1997 while benfluorex remained available until 2009. In this work, the metabolism of benfluorex is simulated by an online hyphenation of electrochemistry and mass spectrometry and the observed transformation products are further characterized using liquid chromatography and high-resolution tandem mass spectrometry. Using this approach, norfenfluramine is found to be the main electrochemical transformation product of benfluorex. Considering the knowledge about norfenfluramine toxicity, rapid metabolite screening using electrochemistry hyphenated to mass spectrometry could have been used to predict the potential of benfluorex for adverse drug reactions early on, showcasing the value of electrochemical metabolism mimicry for rapid drug safety evaluation.

Pharmacotherapy for obesity: recent evolution and implications for cardiovascular risk reduction

INTRODUCTION

Obesity is highly prevalent in the U.S. and is associated with an increased risk of major adverse cardiovascular events (MACE). Modalities for the management of obesity include lifestyle intervention, pharmacotherapy, and bariatric surgery.

AREAS COVERED

This review describes the evidence on the effects of weight loss therapies on MACE risk. Lifestyle interventions and older antiobesity pharmacotherapies have been associated with <12% body weight reduction and no clear benefit to reduce MACE risk. Bariatric surgery is associated with substantial weight reduction (20-30%) and markedly lower subsequent risk for MACE. Newer antiobesity pharmacotherapies, particularly semaglutide and tirzepatide, have shown greater efficacy for weight reduction compared with older medications and are being evaluated in cardiovascular outcomes trials.

EXPERT OPINION

Current practice for cardiovascular risk reduction in patients with obesity is lifestyle intervention for weight loss, combined with the treatment of obesity-related cardiometabolic risk factors individually. The use of medications to treat obesity is relatively rare. In part, this reflects concerns about long-term safety and weight loss effectiveness, possible provider bias, as well as lack of clear evidence of MACE risk reduction. If ongoing outcomes trials demonstrate the efficacy of newer agents in reducing MACE risk, this will likely lead to expanded use in obesity management.

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.

Chiral Switch: Between Therapeutical Benefit and Marketing Strategy

Chirality of pharmaceutical substances is an important aspect in drug research because it determines how enantiomers will interact with chiral biological targets. Enantiomers of a chiral drug can have different pharmacokinetic and pharmacological profiles; consequently, using a single pure enantiomer instead of a racemate can enhance the effectiveness and/or safety of the treatment. The tendencies of modern pharmaceutical industry regarding the current market of chiral drugs are divided between the chiral switch of previously used racemates and the development of new enantiopure drugs. The term chiral switch refers to the replacement on the market of a previously approved racemate with its single enantiomer version. The potential advantages of chiral switch can be related to a higher therapeutic index due to better potency, selectivity and fewer adverse effects, faster onset of action and exposure of the patient to lower drug dosages. However, chiral switch is also a strategy that permits manufacturers to keep market exclusivity for chiral pharmaceuticals that have lost their patent protection, even if the pure enantiomers have not demonstrated higher effectiveness or safety profile compared with the racemates.

Central 5-HTR2C in the Control of Metabolic Homeostasis

The 5-hydroxytryptamine 2C receptor (5-HTR2C) is a class G protein-coupled receptor (GPCR) enriched in the hypothalamus and the brain stem, where it has been shown to regulate energy homeostasis, including feeding and glucose metabolism. Accordingly, 5-HTR2C has been the target of several anti-obesity drugs, though the associated side effects greatly curbed their clinical applications. Dissecting the specific neural circuits of 5-HTR2C-expressing neurons and the detailed molecular pathways of 5-HTR2C signaling in metabolic regulation will help to develop better therapeutic strategies towards metabolic disorders. In this review, we introduced the regulatory role of 5-HTR2C in feeding behavior and glucose metabolism, with particular focus on the molecular pathways, neural network, and its interaction with other metabolic hormones, such as leptin, ghrelin, insulin, and estrogens. Moreover, the latest progress in the clinical research on 5-HTR2C agonists was also discussed.

Drug-associated valvular heart diseases and serotonin-related pathways: a meta-analysis

OBJECTIVE

Serotonergic appetite suppressants and ergot-derived dopamine agonists have been associated with drug-induced valvular heart disease. The purpose of this meta-analysis is to synthesise the current evidence of a link between several medications affecting sertonergic pathways and valvular heart disease.

METHODS

PubMed was searched to identify studies evaluating an association between medications with serotonergic activity and cardiac valvular pathology. Case reports, uncontrolled studies and in vitro studies were excluded. Relevant studies were assessed for quality and potential bias; those of adequate quality were included in a quantitative synthesis. Sensitivity analyses were conducted, and potential publication bias was examined.

RESULTS

There was a consistent, significant relationship between certain medications and heart valve disease, including serotonergic medications (OR 3.30, 95% CI 1.99 to 5.49) and dopaminergic medications (OR 2.56, 95% CI 1.68 to 3.91). Subanalyses, including analyses that limited exposure to a single medication or effects to a single heart valve were also consistently significant. Most studies were retrospective or observational in nature, with a higher risk of selection and presentation biases. There was significant heterogeneity and variability between studies, particularly when it came to dose and duration of exposure.

CONCLUSIONS

There was a consistent, significant association between many medications that affect serotonergic pathways and valvular heart disease. Although many of these medications have been withdrawn from the market, some small studies suggest that recreational drug 3,4-methylenedioxy​methamphetamine and widely prescribed selective serotonin reuptake inhibitors may affect similar pathways.

The safety of pharmacologic treatment for pediatric obesity

INTRODUCTION

Pediatric obesity is a serious public health concern. Five medications have been approved by the Food and Drug Administration (FDA) for chronic weight management in adults with obesity, when used as an adjunct to lifestyle modification. Orlistat is the only FDA-approved medication for pediatric patients aged 12 years and above.

AREAS COVERED

This paper summarizes safety and efficacy data from clinical trials of weight loss medications conducted among pediatric samples. Relevant studies were identified through searches in PubMed.

EXPERT OPINION

Orlistat, as an adjunct to lifestyle modification, results in modest weight losses and may be beneficial for some pediatric patients with obesity. However, gastrointestinal side effects are common and may limit use. In adults taking orlistat, rare but severe adverse events, including liver and renal events, have been reported. Recent pediatric pharmacokinetic studies of liraglutide have demonstrated similar safety and tolerability profiles as found in adults, with gastrointestinal disorders being the most common adverse events. Clinical trials are needed of liraglutide, as well as other medications for obesity, that systematically evaluate their risks and benefits in pediatric patients.

Cardiovascular safety of low-dose fenfluramine in Dravet syndrome: a review of its benefit-risk profile in a new patient population

OBJECTIVE

Dravet syndrome (DS) is a rare, treatment-resistant epilepsy syndrome for which current treatment regimens are often ineffective. Fenfluramine is currently in development for treatment of DS, based on reports in the 1980s and 1990s of its anti-epileptic activity in pediatric patients with intractable epilepsy. However, fenfluramine was withdrawn from global markets in 1997 following reports of its association with pulmonary hypertension and heart valve disease in adult patients treated for obesity. This review was conducted to assess cardiac safety of fenfluramine when used at lower doses for treatment of DS.

METHODS

Pubmed was searched for clinical studies of fenfluramine in obese adults who reported incidence of heart valve disease. These data were reviewed against published results from Belgian patients with DS who have been treated with low-dose fenfluramine for up to 28 years.

RESULTS

Nine controlled studies of fenfluramine and related compounds (dexfenfluramine and/or phentermine) which assessed incidence and severity of cardiac valve disease in 3,268 treated patients and 2,017 control subjects have been reported. Mild or greater aortic valve regurgitation was found in 9.6% of treated patients compared with 3.9% of control subjects, and moderate or greater mitral valve regurgitation was found in 3.1% of treated patients and 2.5% of control subjects. Nineteen DS patients have been treated for up to 28 years with 10-20 mg/day fenfluramine, with no clinical signs or symptoms of cardiac valve disease or pulmonary hypertension. Slight and clinically unimportant changes in valve structure have been seen on echocardiography in five patients at some time during the observation period.

CONCLUSIONS

A different benefit-risk relationship appears to be emerging when fenfluramine is used at low doses for extended periods in young patients with DS. Continued cardiac assessments during ongoing Phase 3 clinical trials will provide additional safety information for this potential new and effective treatment.

The Salford Lung Study: a pioneering comparative effectiveness approach to COPD and asthma in clinical trials

The Salford Lung Study (SLS) of patients with asthma and chronic obstructive pulmonary disease (COPD) is a practical, community-based, randomized, open-label pragmatic study on the efficacy and safety of the once-daily dry powder inhaler that combines the inhaled corticosteroid fluticasone furoate (FF) with the long-acting beta₂ agonist vilanterol (VI). The asthma component of the SLS is not yet reported but the COPD component, done over a 12-month period, found a statistically significant 8.4% reduction in COPD exacerbations when compared to usual care. No differences in adverse events, including serious adverse events and pneumonia, were noted. The importance of real-world findings, such as those found in the SLS COPD trial with inhaled FF/VI, is discussed in comparison to classical randomized controlled trials (RCTs) with inhaled FF/VI in COPD patients. The real-world, community-based pragmatic RCT like the SLS provides additional generalizable data with direct clinical applicability and potential usefulness in the development of practice guidelines. The results from the SLS, along with those of large and small RCTs, are supportive of the use of once-daily FF/VI in COPD maintenance therapy.

Pharmacotherapy for Dravet Syndrome

Dravet syndrome (DS) is an intractable pediatric epilepsy syndrome, starting in early childhood. This disorder typically manifests with febrile status epilepticus, and progresses to a multifocal epilepsy with febrile and non-febrile seizures with encephalopathy. Most cases are due to a mutation in the SCN1A gene. This article reviews treatments for DS, with an emphasis on pharmacotherapy. While many medications are used in treating the seizures associated with DS, these patients typically have medically refractory epilepsy, and polytherapy is often required. First-line agents include valproate and clobazam, although there are supportive data for topiramate, levetiracetam, stiripentol and the ketogenic diet. Other agents such as fenfluramine are promising therapies for Dravet syndrome. Sodium channel-blocking anticonvulsants such as carbamazepine and lamotrigine are generally contraindicated in this syndrome. Nonpharmacologic therapies (such as neurostimulation or surgery) are understudied in DS. Because DS is a global encephalopathy, pharmacologic treatment of non-epileptic manifestations of the disease is often necessary. Attention-deficit hyperactivity disorder is often encountered in patients with DS, and psychostimulants can be helpful for this indication. Other psychoactive drugs are less studied in this context. Extrapyramidal and gait disorders are often encountered in DS as well. While DS is a severe epileptic encephalopathy with a high (up to 15 %) mortality rate in childhood, careful pharmacologic management can improve these patients' clinical picture and quality of life.

Risk of cardiac valvulopathy with use of bisphosphonates: a population-based, multi-country case-control study

Analyses of healthcare data from 30 million individuals in three countries showed that current use of bisphosphonates may be associated with a small increased risk of cardiac valvulopathy (vs. those not exposed within the previous year), although confounding cannot be entirely ruled out. The observed tendency for decreased valvulopathy risk with cumulative duration of bisphosphonate use >6 months may even indicate a protective effect with prolonged use. Further studies are still needed to evaluate whether bisphosphonates increase or decrease the risk of valvulopathy.

INTRODUCTION

A signal of cardiac valve disorders with use of bisphosphonates was identified in the literature and EudraVigilance database, which contains reports of suspected adverse drug reactions from worldwide sources. The aim of this study was to evaluate the association using population-based healthcare data.

METHODS

This was a case-control study among users of bisphosphonates and other drugs for osteoporosis in six healthcare databases covering over 30 million individuals in Italy, Netherlands and the UK from 1996 to 2012. Prescriptions/dispensations were used to assess drug exposure. Newly diagnosed cases of cardiac valvulopathy were identified via disease codes/free-text search. Controls were matched to each case by age, sex, database and index date. Adjusted odds ratios (ORs) were estimated using conditional logistic regression for the pooled data and meta-analysis of individual database risk estimates.

RESULTS

A small but statistically significant association was found between exposure to bisphosphonates as a class and risk of valvulopathy. Overall risk was 18 % higher (95 % CI 12-23 %) in those currently exposed to any bisphosphonate (mainly alendronate and risedronate) vs. those not exposed within the previous year. Risk of valve regurgitation was 14 % higher (95 % CI 7-22 %). Decreased valvulopathy risk was observed with longer cumulative duration of bisphosphonate use, compared to use of less than 6 months. Meta-analyses of database-specific estimates confirmed results from pooled analyses.

CONCLUSIONS

The observed increased risks of cardiac valvulopathy with bisphosphonate use, although statistically significant, were quite small and unlikely to be clinically significant. Further studies are still needed to evaluate whether bisphosphonates increase or decrease the risk of valvulopathy and to investigate possible mechanisms for the association.

Acute pergolide exposure stiffens engineered valve interstitial cell tissues and reduces contractility in vitro

Medications based on ergoline-derived dopamine and serotonin agonists are associated with off-target toxicities that include valvular heart disease (VHD). Reports of drug-induced VHD resulted in the withdrawal of appetite suppressants containing fenfluramine and phentermine from the US market in 1997 and pergolide, a Parkinson's disease medication, in 2007. Recent evidence suggests that serotonin receptor activity affected by these medications modulates cardiac valve interstitial cell activation and subsequent valvular remodeling, which can lead to cardiac valve fibrosis and dysfunction similar to that seen in carcinoid heart disease. Failure to identify these risks prior to market and continued use of similar drugs reaffirm the need to improve preclinical evaluation of drug-induced VHD. Here, we present two complimentary assays to measure stiffness and contractile stresses generated by engineered valvular tissues in vitro. As a case study, we measured the effects of acute (24 h) pergolide exposure to engineered porcine aortic valve interstitial cell (AVIC) tissues. Pergolide exposure led to increased tissue stiffness, but it decreased both basal and active contractile tone stresses generated by AVIC tissues. Pergolide exposure also disrupted AVIC tissue organization (i.e., tissue anisotropy), suggesting that the mechanical properties and contractile functionality of these tissues are governed by their ability to maintain their structure. We expect further use of these assays to identify off-target drug effects that alter the phenotypic balance of AVICs, disrupt their ability to maintain mechanical homeostasis, and lead to VHD.

Dyskinesias and impulse control disorders in Parkinson's disease: From pathogenesis to potential therapeutic approaches

Dopaminergic treatment in Parkinson's disease (PD) reduces the severity of motor symptoms of the disease. However, its chronic use is associated with disabling motor and behavioral side effects, among which levodopa-induced dyskinesias (LID) and impulse control disorders (ICD) are the most common. The underlying mechanisms and pathological substrate of these dopaminergic complications are not fully understood. Recently, the refinement of imaging techniques and the study of the genetics and molecular bases of LID and ICD indicate that, although different, they could share some features. In addition, animal models of parkinsonism with LID have provided important knowledge about mechanisms underlying such complications. In contrast, animal models of parkinsonism and abnormal impulsivity, although useful regarding some aspects of human ICD, do not fully resemble the clinical phenotype of ICD in patients with PD, and until now have provided limited information. Studies on animal models of addiction could complement the previous models and provide some insights into the background of these behavioral complications given that ICD are regarded as behavioral addictions. Here we review the most relevant advances in relation to imaging, genetics, biochemistry and pharmacological interventions to treat LID and ICD in patients with PD and in animal models with a view to better understand the overlapping and unique maladaptations to dopaminergic therapy that are associated with LID and ICD.

Therapeutic Potential of 5-HT2C Receptor Agonists for Addictive Disorders

The neurotransmitter 5-hydroxytryptamine (5-HT; serotonin) has long been associated with the control of a variety of motivated behaviors, including feeding. Much of the evidence linking 5-HT and feeding behavior was obtained from studies of the effects of the 5-HT releaser (dex)fenfluramine in laboratory animals and humans. Recently, the selective 5-HT2C receptor agonist lorcaserin received FDA approval for the treatment of obesity. This review examines evidence to support the use of selective 5-HT2C receptor agonists as treatments for conditions beyond obesity, including substance abuse (particularly nicotine, psychostimulant, and alcohol dependence), obsessive compulsive, and excessive gambling disorder. Following a brief survey of the early literature supporting a role for 5-HT in modulating food and drug reinforcement, we propose that intrinsic differences between SSRI and serotonin releasers may have underestimated the value of serotonin-based pharmacotherapeutics to treat clinical forms of addictive behavior beyond obesity. We then highlight the critical involvement of the 5-HT2C receptor in mediating the effect of (dex)fenfluramine on feeding and body weight gain and the evidence that 5-HT2C receptor agonists reduce measures of drug reward and impulsivity. A recent report of lorcaserin efficacy in a smoking cessation trial further strengthens the idea that 5-HT2C receptor agonists may have potential as a treatment for addiction. This review was prepared as a contribution to the proceedings of the 11th International Society for Serotonin Research Meeting held in Hermanus, South Africa, July 9-12, 2014.

Tolerability and safety of the new anti-obesity medications

Worldwide obesity prevalence has nearly doubled since 1980. Due to numerous co-morbidities, obesity represents a serious health and socioeconomic problem worldwide. Pharmacotherapy should be an integral part of comprehensive obesity management. Drug therapy can assist in weight loss and its maintenance in those individuals who do not achieve appropriate weight loss through lifestyle interventions alone. After the withdrawal of sibutramine from the market in 2010, orlistat, a lipase inhibitor, was the only remaining prescription drug approved for the long-term treatment of obesity. In 2012, phentermine/topiramate extended-release (PHEN/TPM ER) combination and lorcaserin were approved by the US FDA as novel medications for long-term weight management. Three major phase III trials conducted with each drug confirmed their efficacy in terms of weight loss/maintenance and improvement of cardiometabolic risks. No head-to-head studies between the two new anti-obesity drugs have been carried out. However, in the existing studies PHEN/TPM ER had a superior weight loss profile to lorcaserin but the incidence of adverse effects was lower with lorcaserin. Both drugs were well-tolerated, and adverse events were modest in intensity, dose dependent, rather rare, and tended to decrease with the duration of treatment. Major safety concerns regarding PHEN/TPM ER include elevations in resting pulse rate, teratogenicity, mild metabolic acidosis, and psychiatric and cognitive adverse events. Valvulopathy, cognitive impairment, psychiatric disorders, and hypoglycemia represent major safety concerns for lorcaserin. Although existing trials have not demonstrated any significant issues with PHEN/TPM ER-induced heart rate elevation and lorcaserin-induced valvulopathy, all safety concerns should be seriously taken into account in patients treated with either of these novel anti-obesity medications.

Treating the metabolic syndrome

The metabolic syndrome (MS), a cluster of metabolic abnormalities with insulin resistance as its central component, is increasing in prevalence and is associated with an increased risk of cardiovascular disease and Type 2 diabetes mellitus (T2DM). Current evidence supports an aggressive intervention approach that comprises lifestyle modification in conjunction with drug treatment of the MS components. Healthier eating and regular exercise greatly reduce waistline and body mass index, lower blood pressure and improve lipid profile. Lifestyle modification has been proven to prevent T2DM development. Nevertheless, appropriate treatment of MS components often requires pharmacologic intervention with insulin-sensitizing agents, such as metformin and thiazolidinediones, while statins and fibrates, or angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers are the first-line lipid-modifying or antihypertensive drugs. Only severely obese patients require specific drug treatments. Very often, drug combinations will be necessary to manage multiple risk factors. As we progress in the understanding of the pathophysiology of the MS, new targets for therapies will probably be identified and new treatments will prove to be even more efficacious than those currently available for the management of this life-threatening condition.

Severe obesity in children and adolescents: identification, associated health risks, and treatment approaches: a scientific statement from the American Heart Association

Severe obesity afflicts between 4% and 6% of all youth in the United States, and the prevalence is increasing. Despite the serious immediate and long-term cardiovascular, metabolic, and other health consequences of severe pediatric obesity, current treatments are limited in effectiveness and lack widespread availability. Lifestyle modification/behavior-based treatment interventions in youth with severe obesity have demonstrated modest improvement in body mass index status, but participants have generally remained severely obese and often regained weight after the conclusion of the treatment programs. The role of medical management is minimal, because only 1 medication is currently approved for the treatment of obesity in adolescents. Bariatric surgery has generally been effective in reducing body mass index and improving cardiovascular and metabolic risk factors; however, reports of long-term outcomes are few, many youth with severe obesity do not qualify for surgery, and access is limited by lack of insurance coverage. To begin to address these challenges, the purposes of this scientific statement are to (1) provide justification for and recommend a standardized definition of severe obesity in children and adolescents; (2) raise awareness of this serious and growing problem by summarizing the current literature in this area in terms of the epidemiology and trends, associated health risks (immediate and long-term), and challenges and shortcomings of currently available treatment options; and (3) highlight areas in need of future research. Innovative behavior-based treatment, minimally invasive procedures, and medications currently under development all need to be evaluated for their efficacy and safety in this group of patients with high medical and psychosocial risks.

Frequency of drug-induced valvular heart disease in patients previously exposd to benfluorex: a multicentre prospective study

AIMS

The epidemiologic link between benfluorex use and an increased global frequency of left heart valve regurgitation has been well documented. However, no data linking previous drug exposure to the frequency of diagnosis of drug-induced valvular heart disease (DI-VHD) are available. The present study was conducted to address this issue.

METHODS AND RESULTS

This echocardiography reader-blinded, controlled study conducted in 10 centres between February 2010 and February 2012 prospectively included 835 subjects previously exposed to benfluorex referred by primary care physicians for echocardiography. Based on blinded off-line analysis, echocardiography findings were classified as: (i) DI-VHD⁺ for patients with an echocardiographic diagnosis of DI-VHD, (ii) inconclusive, and (iii) DI-VHD⁻ for patients without signs of DI-VHD. Fifty-seven (6.8%) patients exposed to benfluorex were classified as DI-VHD⁺, 733 (87.8%) patients were classified as DI-VHD⁻, and 45 (5.4%) were classified as inconclusive. Mitral and aortic DI-VHD were reported in 43 patients (5.1%) and 30 (3.6%) patients, respectively. Longer duration of exposure, female gender, smoking, and lower BMI were independently associated with a diagnosis of DI-VHD. Good inter-observer reproducibility was observed for the echocardiography classification (Kappa = 0.83, P < 0.00001).

CONCLUSIONS

About 7% of patients without a history of heart valve disease previously exposed to benfluorex present echocardiography features of DI-VHD. Further studies are needed to study the natural history of DI-VHD and to identify risk factors for the development of drug-induced valve lesions.

Serum serotonin concentration is associated with severity of myxomatous mitral valve disease in dogs

BACKGROUND

The neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) has recently been suggested to play a role in the development of naturally acquired myxomatous mitral valve disease (MMVD) in dogs.

AIM

To investigate the association between serum 5-HT concentration and MMVD severity in dogs, and to assess potential associations between serum 5-HT concentrations and dog characteristics, echocardiographic variables, heart rate, systolic blood pressure, presence of macrothrombocytosis, and plateletcrit.

ANIMALS

A total of 120 client-owned dogs.

MATERIAL AND METHODS

Dogs were prospectively recruited and were classified by standard echocardiography into healthy (dogs of breeds predisposed to MMVD, but without echocardiographic evidence of the disease), mild, moderate, or severe MMVD groups. Serum 5-HT concentrations were analyzed using an ELISA.

RESULTS

Dogs with severe MMVD had lower serum 5-HT concentrations than healthy dogs (P = .0025) and dogs with mild MMVD (P = .0011). Unilinear and multiple regression analyses showed that serum 5-HT concentrations decreased with increasing left atrial to aortic root ratio (LA/Ao), were higher in Cavalier King Charles Spaniel (CKCS) dogs compared to dogs of other breeds, and were higher in female dogs than in male dogs. The LA/Ao was the variable most strongly associated with serum 5-HT concentration.

CONCLUSIONS AND CLINICAL IMPORTANCE

The finding of higher serum 5-HT concentrations in dogs of breeds predisposed to the early onset of MMVD (CKCS) and dogs with mild MMVD suggests that alterations in 5-HT signaling might play a role in progression of early stages of MMVD.

Increased risk of left heart valve regurgitation associated with benfluorex use in patients with diabetes mellitus: a multicenter study

BACKGROUND

Benfluorex was withdrawn from European markets in June 2010 after reports of an association with heart valve lesions. The link between benfluorex and valve regurgitations was based on small observational studies and retrospective estimations. We therefore designed an echocardiography-based multicenter study to compare the frequency of left heart valve regurgitations in diabetic patients exposed to benfluorex for at least 3 months and in diabetic control subjects never exposed to the drug.

METHODS AND RESULTS

This reader-blinded, controlled study conducted in 10 centers in France between February 2010 and September 2011 prospectively included 376 diabetic subjects previously exposed to benfluorex who were referred by primary care physicians for echocardiography and 376 diabetic control subjects. Through the use of propensity scores, 293 patients and 293 control subjects were matched for age, sex, body mass index, smoking, dyslipidemia, hypertension, and coronary artery disease. The main outcome measure was the frequency of mild or greater left heart valve regurgitations. In the matched sample, the frequency and relative risk (odds ratio) of mild or greater left heart valve regurgitations were significantly increased in benfluorex patients compared with control subjects: 31.0% versus 12.9% (odds ratio, 3.55; 95% confidence interval, 2.03-6.21) for aortic and/or mitral regurgitation, 19.8% versus 4.7% (odds ratio, 5.29; 95% confidence interval, 2.46-11.4) for aortic regurgitation, and 19.4% versus 9.6% (odds ratio, 2.38; 95% confidence interval, 1.27-4.45) for mitral regurgitation.

CONCLUSIONS

Our results indicate that the use of benfluorex is associated with a significant increase in the frequency of left heart valve regurgitations in diabetic patients. The natural history of benfluorex-induced valve abnormalities needs further research.

Fenfluramine-induced gene dysregulation in human pulmonary artery smooth muscle and endothelial cells

Fenfluramine is prescribed either alone or in combination with phentermine as part of Fen-Phen, an anti-obesity medication. Fenfluramine was withdrawn from the US market in 1997 due to reports of heart valvular disease, pulmonary arterial hypertension, and cardiac fibrosis. Particularly, idiopathic pulmonary arterial hypertension (IPAH), previously referred to as primary pulmonary hypertension (PPH), was found to be associated with the use of Fen-Phen, fenfluramine, and fenfluramine derivatives. The underlying mechanism of fenfluramine-associated pulmonary hypertension is still largely unknown. We reasoned that investigating drug-induced gene dysregulation would enhance our understanding of the fenfluramine-associated pathogenic mechanism of IPAH. Whole-genome gene expression profiles in fenfluramine-treated human pulmonary artery smooth muscle (PASMC) and endothelial (PAEC) cells (isolated from normal subjects) were compared with baseline expression in untreated cells. Fenfluramine treatment caused dysregulation in a substantial number of genes involved in a variety of pathways and biological processes. In addition to several common pathways and biological processes such as "MAPK signaling pathway," "inflammation response," and "calcium signaling pathway" shared between both cell types, pathways and biological processes such as "blood circulation," "muscle system process," and "immune response" were enriched among the dysregulated genes in PASMC. Pathways and biological processes such as those related to cell cycle, however, were enriched among the dysregulated genes in PAEC, indicating that fenfluramine could affect unique pathways (or differentially) in different types of pulmonary artery cells. While awaiting validation in a larger cohort, these results strongly suggested that fenfluramine could induce significant dysregulation of genes in multiple biological processes and pathways critical for normal pulmonary vascular functions and structure. The transcriptional and posttranscriptional changes in these genes may, therefore, contribute to the pathogenesis of fenfluramine-associated IPAH.

Pharmacological management of binge eating disorder: current and emerging treatment options

Growing evidence suggests that pharmacotherapy may be beneficial for some patients with binge eating disorder (BED), an eating disorder characterized by repetitive episodes of uncontrollable consumption of abnormally large amounts of food without inappropriate weight loss behaviors. In this paper, we provide a brief overview of BED and review the rationales and data supporting the effectiveness of specific medications or medication classes in treating patients with BED. We conclude by summarizing these data, discussing the role of pharmacotherapy in the BED treatment armamentarium, and suggesting future areas for research.

A review of late-stage CNS drug candidates for the treatment of obesity

Obesity is an important causative factor in morbidity, disability and premature death. Increasing levels of obesity will impose enormous health, financial and social burdens on worldwide society unless effective interventions are implemented. For many obese individuals, diet and behavioural modification need to be supplemented by pharmacotherapy. Preclinical research has revealed a greater understanding of the complex nature of the hypothalamic regulation of food intake and has generated a wide range of new molecular targets for the development of drug candidates for obesity treatment. As shown by the clinical results that have been obtained with this next generation of therapies, some approaches, for example, fixed-dose drug combinations, have already demonstrated an ability to deliver levels of efficacy that are not achievable with the current antiobesity drug therapies. The regulatory and marketing landscape for development, registration and commercialisation of novel centrally acting drugs for treatment of obesity and related metabolic disorders has changed substantially in recent years. Now a much greater emphasis is placed on tolerability and safety, as well as efficacy. In this review we briefly describe the therapeutic approaches to tackle obesity that are in late-stage clinical development. We then discuss drugs in late-stage development for the treatment of obesity and also future directions.

Estimate of deaths due to valvular insufficiency attributable to the use of benfluorex in France

PURPOSE

To estimate the number of deaths from valvular insufficiency caused by the use of the fenfluramine-derivative benfluorex during the period 1976-2009 in France.

METHODS

Our calculation was based on (i) the exposure level to benfluorex in the French population, derived from sales figures for the period 1976-2009 and from the main characteristics of benfluorex use provided by the French health products safety agency; (ii) the relative risk of hospitalization for valvular insufficiency among exposed compared with unexposed individuals with diabetes, originating from a cohort study based on a French medico-administrative database, with benfluorex exposure assessed in 2006; (iii) the incidence of hospitalization for valvular insufficiency among exposed individuals, originating from the same database; and (iv) the mortality associated with valvular heart disease.

RESULTS

In France, use of benfluorex during the period 1976-2009 is likely to be responsible for around 3100 hospitalizations and 1300 deaths due to valvular insufficiency. These figures may be underestimations.

CONCLUSIONS

The grave consequences benfluorex use have had for many people lend support to the public investigation, which has been set to understand the reasons that have contributed to the delay in withdrawing benfluorex from the French market.

Does innovation in obesity drugs affect stock markets? An event study analysis

OBJECTIVE

This study empirically analyzes the effects of public information about the pharmaceutical R&D process on the market valuation of the sponsoring firm. We examined the market's response to scientific news and regulatory decisions about an antiobesity drug, rimonabant, and the effects on the sponsoring company (Sanofi-Aventis) and its incumbent competitors (Abbott and Roche).

METHODS

Event study methodology was used to test the null hypothesis of no market response. We covered the full life cycle of rimonabant (1994-2008), using a data set of daily closing price and volume.

RESULTS

The results suggest that scientific news in the initial stages of the drug R&D process (i.e., drug discovery, preclinical and clinical trials) had no significant effects. However, news related to regulatory decisions, such as recall or safety warning, had significant negative effects on the company's market value. No spillover/contagion effects on competitor firms were detected.

CONCLUSION

Market reactions occur at the time when the regulator takes decisions about drugs. Scientific news, even those of high-impact, may pass unnoticed.

Pharmacologic management of obesity

Recent discoveries of processes that govern regulation of body weight and energy expenditure have led to development of new anti-obesity pharmacological agents. This article will inform health professionals of new anti-obesity medications that target neuronal systems within the central nervous system (CNS) and peripheral humoral proteins that send signals to the CNS. An emerging theme of new therapies is to use combination medications that are directed toward several targets or leverage existing gastrointestinal satiety hormonal signals. By using combination therapies, it is anticipated that greater weight loss will be achieved compared to monotherapy.

Drug treatment for obesity in the post-sibutramine era

Obesity is a major health problem worldwide. It is associated with cardiovascular diseases, diabetes mellitus and decreased longevity. In managing obesity, diet and exercise are essential; pharmacological therapy may be added for obese patients or overweight patients with cardiovascular risk factors. Sibutramine is a serotonergic and adrenergic drug that reduces food intake and increases thermogenesis. It reduces bodyweight by about 4.2 kg after 12 months, and improves blood glucose and lipids; however, it can increase heart rate and blood pressure. In the SCOUT (Sibutramine Cardiovascular OUTcomes) study, sibutramine increased serious cardiovascular events, such as stroke or myocardial infarction, compared with placebo, and was consequently withdrawn from the market. The lesson learnt from this is the importance of patient selection, limiting the duration of treatment and stopping treatment in non-responders. Currently, phentermine and amfepramone (diethylpropion) are approved for short-term treatment of obesity (up to 3 months) and orlistat is approved for longer-term treatment; however, the gastrointestinal adverse effects of orlistat may be intolerable for some patients. There is now a clear need to find anti-obesity drugs that are effective and safe in the long term.

Ontogeny and regulation of the serotonin transporter: providing insights into human disorders

Serotonin (5-hydroxytryptamine, 5-HT) was one of the first neurotransmitters for which a role in development was identified. Pharmacological and gene knockout studies have revealed a critical role for 5-HT in numerous processes, including cell division, neuronal migration, differentiation and synaptogenesis. An excess in brain 5-HT appears to be mechanistically linked to abnormal brain development, which in turn is associated with neurological disorders. Ambient levels of 5-HT are controlled by a vast orchestra of proteins, including a multiplicity of pre- and post-synaptic 5-HT receptors, heteroreceptors, enzymes and transporters. The 5-HT transporter (SERT, 5-HTT) is arguably the most powerful regulator of ambient extracellular 5-HT. SERT is the high-affinity uptake mechanism for 5-HT and exerts tight control over the strength and duration of serotonergic neurotransmission. Perturbation of its expression level or function has been implicated in many diseases, prominent among them are psychiatric disorders. This review synthesizes existing information on the ontogeny of SERT during embryonic and early postnatal development though adolescence, along with factors that influence its expression and function during these critical developmental windows. We integrate this knowledge to emphasize how inappropriate SERT expression or its dysregulation may be linked to the pathophysiology of psychiatric, cardiovascular and gastrointestinal diseases.

Oleoyl-estrone

Oleoyl-estrone (OE) is a powerful slimming agent that is also present in plasma and adipose tissue, where it is synthesized. It acts through the formation of a derivative W. OE effects (and W levels) are proportional to the dose. OE reduces food intake but maintains energy expenditure (thermogenesis). The energy gap is fulfilled with adipose tissue fat, sparing body protein and maintaining glycemia (and glycogen) with lower insulin and leptin levels. OE (in fact W) acts through specific receptors, different from those of estrogen. OE increases cholesterol catabolism, reducing hypercholesterolemia in obese rats. The main metabolic effect on adipose tissue is lowering of lipid synthesis, maintaining unchanged the intracellular lipolytic processes; the imbalance favors the progressive loss of fat, which is largely used by the muscle. OE administration induces additive effects with other antiobesity agents, such as β(3)-adrenergic agonists, forcing a massive loss of lipid. Corticosteroids markedly limit OE action by altering the liver control of lipogenesis. OE also inhibits the action of 17β-hydroxysteroid dehydrogenase, decreasing the synthesis of β-estradiol and testosterone. Discontinuous treatment allows for maximal efficacy both in rats and humans. OE has the advantage that the loss of fat is maintained and does not require additional dietary limitations.

Valvular heart disease associated with benfluorex therapy: results from the French multicentre registry

AIMS

The aim of this paper is to report clinical characteristics, consequences, echocardiographic features, and pathological findings encountered in patients suffering from valvular disease associated with benfluorex exposure in a multicentre French registry.

METHODS AND RESULTS

Forty patients suffering from unexplained restrictive valvular disease with a previous exposition to benfluorex, a fenfluramine derivative, were identified from eight French university hospitals. Patients were mostly women (87.5%) with a mean age of 57 ± 9 years and high body mass index of 30 ± 7 kg/m²; 37.5% of them presented with severe heart failure symptoms (NYHA class III and IV). Benfluorex mean daily dose was 415 ± 131 mg with total therapy duration of 72 ± 53 months. Resulting cumulative dose was 910 ± 675 g. Common echocardiographic findings were leaflets and sub-valvular apparatus thickening and retraction. Aortic and mitral valve regurgitations resulting from leaflets loss of coaptation were the most frequent findings (87.5 and 82.5%) and were severe in 29 patients (72.5%). Multiple valve involvements were present in 31 cases (77.5%). Pulmonary arterial hypertension was identified in 20 cases (50%). Histopathological examination demonstrated abundant extra cellular matrix encasing the leaflets without modification of valve architecture. Fifteen patients (37.5%) underwent valvular surgery.

CONCLUSION

Benfluorex-related valvulopathy shares numerous characteristics with other drug-induced valvular disease. Clinical consequences may be serious with severe heart failure symptoms that may lead to surgical treatment.

Surgery for carcinoid heart disease: current outcomes, concerns and controversies

Cardiac involvement in patients with carcinoid disease is a well-recognized pathology. Early reports described right-sided heart involvement. More recently, both right- and left-sided heart disease have been reported. Progress of the treatment of carcinoid disease is leading to an increase in the number of patients presenting for surgery to treat valvular dysfunction. owing to improvements in the prognosis of the basic disease, valve replacement surgery is now a reasonable option in patients with severe valvular dysfunction. This article provides an overview of carcinoid heart disease with an emphasis on current outcomes, concerns and controversies associated with the surgical management of this disease.

Regulatory challenges for new drugs to treat obesity and comorbid metabolic disorders

Obesity is a major cause of morbidity and mortality through cardio- and cerebrovascular diseases and cancer. The metabolic consequences of obesity include dyslipidaemia, hypertension, proinflammatory atherogenesis, pre-diabetes and Type 2 diabetes. For a significant proportion of patients, pharmacotherapy to tackle obesity is required as adjunctive support to diet, exercise and lifestyle modification. To this end, the pharmaceutical industry is pursuing many novel drug targets. Although this view is probably not justified, the recent tribulations of rimonabant have created a perception that the regulatory bar for the approval of antiobesity drugs has been raised. Although >5% of placebo-subtracted weight loss maintained over 1 year is the primary efficacy end-point, it is improvements in cardiovascular risk factors that the Food and Drug Administration (FDA) and European Medicines Agency (EMEA) require to grant approval. Safety aspects are also critical in this indication. Many companies are now switching development of their antiobesity drug candidates into other metabolic disorders. Type 2 diabetes is accepted by the industry and FDA, but not EMEA, as the most appropriate alternative. On the other hand, improvements in plasma lipids produced by antiobesity drugs are moderate compared with established therapies, suggesting dyslipidaemia is not a viable development option. Metabolic Syndrome is not accepted by FDA or EMEA as a discrete disease and the agencies will not licence antiobesity drugs for its treatment. The regulatory environment for antiobesity drugs and the spectrum of indications for which they can be approved could change dramatically if positive data for sibutramine emerge from the SCOUT outcome trial.

Adiposopathy: treating pathogenic adipose tissue to reduce cardiovascular disease risk

Excessive adipose tissue is potentially pathogenic due to its mass effects and through adverse metabolic/immune responses, which may lead to cardiovascular disease risk factors (eg, type 2 diabetes mellitus, hypertension, dyslipidemia, and possibly atherosclerosis itself). Positive caloric balance in genetically/environmentally susceptible patients may result in adipocyte hypertrophy, visceral adipose tissue accumulation, and ectopic fat deposition, all causally associated with metabolic disease, and all anatomic manifestations of "adiposopathy" (a term used to describe adipose tissue pathology). Weight loss through improved nutrition, increased physical activity, and weight loss agents (ie, orlistat and sibutramine) improves adiposopathy and improves many metabolic diseases whose prevalence are directly associated with an increase in body fat and sedentary lifestyle. Cannabinoid receptor antagonists improve adiposopathy through weight reduction and favorable metabolic effects upon multiple body organs (including adipocytes). Peroxisome proliferator-activated receptor-gamma agonists may improve adiposopathy through recruitment of functional fat cells and apoptosis of dysfunctional fat cells.