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Alfredo Halpern - One of the best experts on this subject based on the ideXlab platform.
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Long-term pharmacotherapy for obesity in elderly patients: a retrospective evaluation of medical records from a specialized obesity outpatient clinic.
Drugs & aging, 2010Co-Authors: Nidia Celeste Horie, Cintia Cercato, Marcio C. Mancini, Alfredo HalpernAbstract:Background Obesity is a serious chronic disease and the prevalence of this condition is increasing among the elderly. Although the benefits of weight loss to improve control of associated diseases are well known in young adults, they are not in older patients. The use of anti-obesity drugs to promote weight loss is widespread in Brazil and other countries, and obesity specialists frequently prescribe medicines in doses and for durations previously unreported in the literature. Sibutramine, orlistat and Amfepramone (diethylpropion) have been evaluated in clinical trials of more than 2 years’ duration in adults, demonstrating safety and efficacy, but long-term studies in obesity treatment are absent for other drugs. The efficacy and safety of obesity pharmacotherapy among the elderly is unknown.
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Long-Term Pharmacotherapy for Obesity in Elderly Patients
Drugs & Aging, 2010Co-Authors: Nidia Celeste Horie, Cintia Cercato, Marcio C. Mancini, Alfredo HalpernAbstract:Background Obesity is a serious chronic disease and the prevalence of this condition is increasing among the elderly. Although the benefits of weight loss to improve control of associated diseases are well known in young adults, they are not in older patients. The use of anti-obesity drugs to promote weight loss is widespread in Brazil and other countries, and obesity specialists frequently prescribe medicines in doses and for durations previously unreported in the literature. Sibutramine, orlistat and Amfepramone (diethylpropion) have been evaluated in clinical trials of more than 2 years’ duration in adults, demonstrating safety and efficacy, but long-term studies in obesity treatment are absent for other drugs. The efficacy and safety of obesity pharmacotherapy among the elderly is unknown. Objective To describe the experience of obesity pharmacotherapy in the elderly in a specialized obesity care setting in Brazil, with a focus on efficacy and safety. Methods A retrospective evaluation was conducted on medical charts from an outpatient clinic of a specialized tertiary centre for the treatment of obesity. We included patients who had had at least one consultation between January and December 2007, were aged ≥60 years at the beginning of the treatment, had had at least 6 months of follow-up and had received a prescription of at least one potential weight-loss drug. Diagnoses reported on medical records were documented. Age, weight, height and body mass index (BMI) were recorded at admission, after 6, 12, 18 and 24 months, and at the last available visit. The medicines prescribed, together with the dose, duration of use, adverse effects and reasons for discontinuation, were documented. Results The group consisted of 44 women (86%) and 7 men (14%), with a mean±SD age of 65.2±4.5 years, weight of 95.3±12.5 kg and BMI of 38.5±4.3kg/m^2. The mean±SD time of follow-up was 39.3±26.4 months, and the mean weight loss was 6.65 kg (p
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This material is the copyright of the original publisher. Unauthorised copying and distribution is prohibited. Long-Term Pharmacotherapy for Obesity in Elderly Patients A Retrospective Evaluation of Medical Records from a Specialized Obesity Outpatie
2010Co-Authors: Nidia Celeste Horie, Cintia Cercato, Marcio C. Mancini, Alfredo HalpernAbstract:Background: Obesity is a serious chronic disease and the prevalence of this condition is increasing among the elderly. Although the benefits of weight loss to improve control of associated diseases are well known in young adults, they are not in older patients. The use of anti-obesity drugs to promote weight loss is widespread in Brazil and other countries, and obesity specialists frequently prescribe medicines in doses and for durations previously unreported in the literature. Sibutramine, orlistat and Amfepramone (diethylpropion) have been evaluated in clinical trials of more than 2 years’ duration in adults, demonstrating safety and efficacy, but long-term studies in obesity treatment are absent for other drugs. The efficacy and safety of obesity pharmacotherapy among the elderly is unknown. Objective: To describe the experience of obesity pharmacotherapy in the elderly in a specialized obesity care setting in Brazil, with a focus on efficacy and safety. Methods: A retrospective evaluation was conducted on medical charts from an outpatient clinic of a specialized tertiary centre for the treatment of obesity. We included patients who had had at least one consultation between January and December 2007, were aged ‡60 years at the beginning of the treatment, had had at least 6 months of follow-up and had received a prescription of at least one potential weight-loss drug. Diagnoses reported on medical records were documented. Age, weight, height and body mass index (BMI) were recorded at admission, after 6, 12, 18 and 24 months, and at the last available visit. The medicines prescribed, together with the dose, duration of use, adverse effects and reasons for discontinuation, were documented. Results: The group consisted of 44 women (86%) and 7 men (14%), with a mean – SD age of 65.2 – 4.5 years, weight of 95.3 – 12.5 kg and BMI of
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Diabesity
Treatments in Endocrinology, 2005Co-Authors: Alfredo Halpern, Marcio C. ManciniAbstract:Weight reduction has been shown to improve glycemic control and cardiovascular risk factors associated with insulin resistance in obese individuals with type 2 diabetes mellitus. Therapeutic options for these patients include promoting weight loss (non-pharmacologic and pharmacologic treatment) and improving glycemic control, as well as treating common associated risk factors such as arterial hypertension and dyslipidemias. This article provides an overview of anti-obesity drugs used in the treatment of obese individuals with type 2 diabetes. The most widely investigated drugs, sibutramine and orlistat, result in modest, clinically worthwhile weight loss, with demonstrable improvements in many co-morbidities, among them, type 2 diabetes. Clinical trials with these anti-obesity medications in cohorts of obese diabetic patients have been reviewed as well as cathecolaminergic agents (diethylpropion [Amfepramone], fenproporex, mazindol, ephedrine-caffeine combination), serotoninergic drugs (fenfluramine, dexfenfluramine, fluoxetine), and other drugs that have some action on weight loss (the antidiabetic agent metformin, anti-epileptic agents topiramate and zonisamide, and the antidepressive bupropion [amfebutamone]). These trials show variable benefits in terms of effects on glucose profiles.
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Diabesity: are weight loss medications effective?
Treatments in endocrinology, 2005Co-Authors: Alfredo Halpern, Marcio C. ManciniAbstract:Weight reduction has been shown to improve glycemic control and cardiovascular risk factors associated with insulin resistance in obese individuals with type 2 diabetes mellitus. Therapeutic options for these patients include promoting weight loss (non-pharmacologic and pharmacologic treatment) and improving glycemic control, as well as treating common associated risk factors such as arterial hypertension and dyslipidemias. This article provides an overview of anti-obesity drugs used in the treatment of obese individuals with type 2 diabetes. The most widely investigated drugs, sibutramine and orlistat, result in modest, clinically worthwhile weight loss, with demonstrable improvements in many co-morbidities, among them, type 2 diabetes. Clinical trials with these anti-obesity medications in cohorts of obese diabetic patients have been reviewed as well as cathecolaminergic agents (diethylpropion [Amfepramone], fenproporex, mazindol, ephedrine-caffeine combination), serotoninergic drugs (fenfluramine, dexfenfluramine, fluoxetine), and other drugs that have some action on weight loss (the antidiabetic agent metformin, anti-epileptic agents topiramate and zonisamide, and the antidepressive bupropion [amfebutamone]). These trials show variable benefits in terms of effects on glucose profiles.
John J Mcneil - One of the best experts on this subject based on the ideXlab platform.
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Pharmacotherapies for Obesity: Past, Current, and Future Therapies
Journal of Obesity, 2010Co-Authors: Lisa L Ioannides-demos, Loretta Piccenna, John J McneilAbstract:Past therapies for the treatment of obesity have typically involved pharmacological agents usually in combination with a calorie-controlled diet. This paper reviews the efficacy and safety of pharmacotherapies for obesity focusing on drugs approved for long-term therapy (orlistat), drugs approved for short-term use (Amfepramone [diethylpropion], phentermine), recently withdrawn therapies (rimonabant, sibutamine) and drugs evaluated in Phase III studies (taranabant, pramlintide, lorcaserin and tesofensine and combination therapies of topiramate plus phentermine, bupropion plus naltrexone, and bupropion plus zonisamide). No current pharmacotherapy possesses the efficacy needed to produce substantial weight loss in morbidly obese patients. Meta-analyses support a significant though modest loss in bodyweight with a mean weight difference of 4.7 kg (95% CI 4.1 to 5.3 kg) for rimonabant, 4.2 kg (95% CI 3.6 to 4.8 kg) for sibutramine and 2.9 kg (95% CI 2.5 to 3.2 kg) for orlistat compared to placebo at ≥12 months. Of the Phase III pharmacotherapies, lorcaserin, taranabant, topiramate and bupropion with naltrexone have demonstrated significant weight loss compared to placebo at ≥12 months. Some pharmacotherapies have also demonstrated clinical benefits. Further studies are required in some populations such as younger and older people whilst the long term safety continues to be a major consideration and has led to the withdrawal of several drugs.
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Review Article Pharmacotherapies for Obesity: Past, Current, and Future Therapies
2010Co-Authors: Lisa L Ioannides-demos, Loretta Piccenna, John J McneilAbstract:Copyright © 2011 Lisa L. Ioannides-Demos et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Past therapies for the treatment of obesity have typically involved pharmacological agents usually in combination with a caloriecontrolled diet. This paper reviews the efficacy and safety of pharmacotherapies for obesity focusing on drugs approved for longterm therapy (orlistat), drugs approved for short-term use (Amfepramone [diethylpropion], phentermine), recently withdrawn therapies (rimonabant, sibutamine) and drugs evaluated in Phase III studies (taranabant, pramlintide, lorcaserin and tesofensine and combination therapies of topiramate plus phentermine, bupropion plus naltrexone, and bupropion plus zonisamide). No current pharmacotherapy possesses the efficacy needed to produce substantial weight loss in morbidly obese patients. Metaanalyses support a significant though modest loss in bodyweight with a mean weight difference of 4.7 kg (95 % CI 4.1 to 5.3 kg) for rimonabant, 4.2 kg (95 % CI 3.6 to 4.8 kg) for sibutramine and 2.9 kg (95 % CI 2.5 to 3.2 kg) for orlistat compared to placebo at ≥12 months. Of the Phase III pharmacotherapies, lorcaserin, taranabant, topiramate and bupropion with naltrexone have demonstrated significant weight loss compared to placebo at ≥12 months. Some pharmacotherapies have also demonstrated clinical benefits. Further studies are required in some populations such as younger and older people whilst the long term safety continues to be a major consideration and has led to the withdrawal of several drugs. 1
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Safety of Drug Therapies Used for Weight Loss and Treatment of Obesity
Drug Safety, 2006Co-Authors: Lisa L Ioannides-demos, Joseph Proietto, Andrew M. Tonkin, John J McneilAbstract:Some of the medications used for weight loss in the management of obesity have been associated with unacceptable morbidity and mortality. Safety concerns have led to the withdrawal of aminorex, followed by the fenfluramines in 1997, and phenylpropanolamine (norephedrine) in 2000. Aminorex was associated with an increased prevalence of primary pulmonary hypertension (PPH), fenfluramines with an increased prevalence of PPH and valvulopathy, and phenylpropanolamine with an increased risk of haemorrhagic stroke. Several studies have investigated the safety of the fenfluramines, yet the benefit-risk profile has not been conclusively quantified. This is due to several deficiencies in the published studies, including a lack of data on the baseline prevalences of comorbid conditions in obese subjects, and potential confounders and biases in the study designs. Although several studies and systematic reviews support an increased risk of PPH and valvulopathy in patients who have taken fenfluramines, without knowledge of the background prevalence it is not possible to determine if the exposure preceded the outcome. The population at higher risk of these adverse effects includes those taking higher doses or with a longer duration of exposure to fenfluramines and those with pre-existing cardiac disease or a genetic predisposition. Patients exposed to fenfluramines continue to be monitored, with some follow-up studies indicating no overall worsening in valvulopathy over time. There are limited efficacy and safety data for Amfepramone (diethylpropion) and phentermine and their approval for the management of obesity is limited to short-term use. Orlistat and sibutramine are the only currently approved medications for long-term management of obesity. Although the benefit-risk profiles of sibutramine and orlistat appear positive, sibutramine continues to be monitored because of long-term safety concerns. The safety and efficacy of currently approved drug therapies have not been evaluated in children and elderly patient populations and there is limited information in adolescents, whilst the long-term safety of current and potential new drug therapies in adults will require several years of postmarketing surveillance to fully elucidate their adverse effect profiles.
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Pharmacotherapy for obesity
Drugs, 2005Co-Authors: Lisa L Ioannides-demos, Joseph Proietto, John J McneilAbstract:Pharmacotherapy for the management of obesity is primarily aimed at weight loss, weight loss maintenance and risk reduction, and has included thyroid hormone, amphetamines, phentermine, Amfepramone (diethylpropion), phenylpropanolamine, mazindol, fenfluramines and, more recently, sibutramine and orlistat. These agents decrease appetite, reduce absorption of fat or increase energy expenditure.
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Pharmacotherapy for Obesity
Drugs, 2005Co-Authors: Lisa L Ioannides-demos, Joseph Proietto, John J McneilAbstract:Pharmacotherapy for the management of obesity is primarily aimed at weight loss, weight loss maintenance and risk reduction, and has included thyroid hormone, amphetamines, phentermine, Amfepramone (diethylpropion), phenylpropanolamine, mazindol, fenfluramines and, more recently, sibutramine and orlistat. These agents decrease appetite, reduce absorption of fat or increase energy expenditure. Primary endpoints used to evaluate anti-obesity drugs most frequently include mean weight loss, percentage weight loss and proportion of patients losing ≥5% and ≥10% of initial body weight. Secondary endpoints may include reduction in body fat, risk factors for cardiovascular disease and the incidences of diseases such as diabetes mellitus. Most pharmacotherapies have demonstrated significantly greater weight loss in patients on active treatment than those receiving placebo in short-term (≤1 year) randomised controlled trials of pharmacological treatment in conjunction with a calorie-controlled diet or lifestyle intervention. The evidence of long-term efficacy is limited to sibutramine (2 years) and orlistat (4 years). These are the only drugs currently approved for the long-term management of obesity in adults. Sibutramine recipients randomised following 6 months’ treatment to either sibutramine or placebo demonstrated significantly better weight maintenance at 2 years than those taking placebo (p < 0.001), with ≥10% loss of initial bodyweight in 46% of patients. For patients taking orlistat, weight loss was 2.2kg greater than those on placebo at 4 years (p < 0.001), with significantly more patients achieving ≥10% loss of initial bodyweight (26.2% and 15.6%, respectively; p < 0.001). Other drugs that have been evaluated for weight loss include ephedrine, the antidepressants fluoxetine and bupropion, and the antiepileptics topiramate and zonisamide. Two clinical trials with fluoxetine both reported no significant difference in weight loss compared with placebo at 52 weeks. Clinical trials evaluating ephedrine, bupropion, topiramate and zonisamide have demonstrated significantly greater weight loss than placebo but have been limited to 16–26 weeks’ treatment. A major obstacle to the evaluation of the clinical trials is the potential bias resulting from low study completion rates. Completion rates varied from 52.8% of phentermine recipients in a 9-month study, to 40% of fenfluramine recipients in a 24-week comparative study with phentermine and 18% of Amfepramone recipients in a 24-week study. One-year completion rates range from 51% to 73% for sibutramine and from 66% to 85% for orlistat. Other potential sources of bias include run-in periods and subsequent patient selection based on compliance or initial weight loss. Several potential new therapies targeting weight loss and obesity through the CNS pathways or peripheral adiposity signals are in early phase clinical trials. Over the next decade the drug treatment of obesity is likely to change significantly because of the availability of new pharmacotherapies to regulate eating behaviours, nutrient partitioning and/or energy expenditure.
Leandro M. De Carvalho - One of the best experts on this subject based on the ideXlab platform.
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A new approach to ion exchange chromatography with conductivity detection for adulterants investigation in dietary supplements.
Biomedical chromatography : BMC, 2019Co-Authors: Thaís Ramos Dal Molin, Leandro M. De Carvalho, Diana Tomazi Muratt, Larissa Sabo Müller, Géssica Domingos Da Silveira, Gabriela Camera Leal, Carine VianaAbstract:The extent of adulteration of dietary supplements has significantly increased in recent years. This situation worries health authorities and requires auxiliary analytical tools for the investigation of illegal substances purposely added. Ion exchange chromatography with conductivity detection is a consolidated analytical technique for the determination of inorganic compounds in various matrices. This technique has been applied to the pharmaceutical characterization of mainly impurities and degradation products. This work presents a new approach to ion exchange chromatography as a screening method to investigate the presence of Amfepramone, femproporex, sibutramine, bisacodyl and amiloride in dietary supplements advertised for weight loss. The method was optimized and validated using a Metrosep C4 100/4.0 cation exchange column. The mobile phase consisted of 1.8 mm HNO3 containing 2% acetonitrile (v/v), with a flow rate of 0.9 ml min-1 , and nonsuppressed conductivity detection was applied. The limits of detection and quantification varied from 1.01 to 3.62 mg L-1 and from 1.48 to 8.72 mg L-1 , respectively. The proposed method was successful applied to 78 solid dietary supplement samples, in two of which adulterations were found. Moreover, ion exchange chromatography with conductivity detection could be easily used for quality control without prior complex sample pre-treatment.
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Pulsed amperometric detection of pharmacologic adulterants in dietary supplements using a gold electrode coupled to HPLC separation
Analytical Methods, 2018Co-Authors: Diana Tomazi Muratt, Thaís Ramos Dal Molin, Carine Viana, Larissa Sabo Müller, Leandro M. De CarvalhoAbstract:The enlargement of the dietary supplement market has been observed in several countries around the world. However, the increasing consumption of these products raises concerns about their quality and safety. Considering the current scenario, the aim of this study was to develop a new method for screening of multiclass drugs as possible adulterants of dietary supplements. Six drug classes (stimulants, anorexics, anxiolytics, antidepressants, diuretics and laxatives) were studied by high performance liquid chromatography using a biphenyl stationary phase and a gold disc as the working electrode for pulsed amperometric detection (HPLC-PAD). A detection potential of +0.8 V proved to be more appropriate for the detection of all the drugs. A mobile phase consisting of 10 mmol L−1 ammonium acetate in 64% (v/v) methanol at pH 4.0 (isocratic system), 1.0 mL min−1 and 40 °C was used as the optimal conditions for chromatographic separations. Fenproporex, Amfepramone, yohimbine, caffeine, sildenafil, tadalafil, furosemide, sertraline, fluoxetine, lorazepam, clonazepam, midazolam, diazepam and bisacodyl were separated after a 25 min chromatographic run. The limits of quantification ranged from 0.13 mg L−1 (fenproporex) to 8.25 mg L−1 (Amfepramone), and accuracies from 86.24 to 114.82%. Ten samples of dietary supplements were analyzed, in which caffeine and yohimbine were determined among the studied drugs.
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Determination of diuretics and laxatives as adulterants in herbal formulations for weight loss
Food additives & contaminants. Part A Chemistry analysis control exposure & risk assessment, 2013Co-Authors: Ana Paula L. Moreira, Carine Viana, Monique Jung Motta, Thaís Ramos Dal Molin, Leandro M. De CarvalhoAbstract:A new method is described for the determination of the most common diuretic and laxative adulterants found in formulations of anorexics and antidepressants. The method is based on the separation of furosemide, hydrochlorothiazide, chlorthalidone and amiloride (diuretics), phenolphthalein (laxative), Amfepramone (anorexic) and fluoxetine and paroxetine (antidepressants) by capillary zone electrophoresis with capacitively coupled contactless conductivity detection. The method showed a precision ranging from 1.9% to 6.9% for a concentration of 25 mg/L, 0.6% to 5.3% for a concentration of 50 mg/L and 1.6% to 6.0% for a concentration of 100 mg/L for all analytes. The accuracy was 99% for amiloride, 102% for chlorthalidone, 101% for hydrochlorothiazide, 101% for furosemide, 94% for phenolphthalein, 105% for fluoxetine, 114% for paroxetine and 117% for Amfepramone. The method allowed the drugs to be determined in the formulations at concentrations higher than 5.1 mg/kg for amiloride, 7.7 mg/kg for chlorthalidone...
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Screening of pharmacologic adulterant classes in herbal formulations using voltammetry of microparticles.
Journal of Pharmaceutical and Biomedical Analysis, 2012Co-Authors: Antonio Doménech-carbó, Mariele Martini, Leandro M. De Carvalho, Carine Viana, María Teresa Doménech-carbó, Miguel F. SilvaAbstract:A solid state electrochemical method for screening different families of adulterant chemicals illegally added to commercial phytotherapuetic formulations is described. The proposed method, based on the voltammetry of microparticles approach, permits a fast and sensitive way to distinguish between anorexics (Amfepramone, fenproporex, sibutramine), benzozodiazepinic anxiolytics (clonazepam, flurazepam, alprazolam, midazolam, medazepam, chlordiazepoxide, diazepam), antidepressants (bupropione, fluoxetine, sertraline, paroxetine), diuretics (hydrochlorothiazide, furosemide, chlortalidone, amiloride, spironolactone), and hypoglycemics (glimepiride, chlorpropamide, glibenclamide) based on characteristic voltammetric signals recorded on solid micro- or nanosamples attached to graphite electrodes immersed into aqueous electrolytes.
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A new method for the simultaneous determination of 1,4-benzodiazepines and Amfepramone as adulterants in phytotherapeutic formulations by voltammetry.
Forensic science international, 2010Co-Authors: Leandro M. De Carvalho, Daniele Correia, Solange C Garcia, André V De Bairros, Paulo C Do Nascimento, Denise BohrerAbstract:The use of synthetic pharmaceuticals in phytotherapeutics can be defined as an illegal practice, since these compounds are normally present as non-declared compounds in the phytotherapeutical formulations. This work aims to show the development of an analytical method based on adsorptive cathodic stripping voltammetry (AdCSV) for the simultaneous determination of 1,4-benzodiazepines and Amfepramone. The developed method was used to measure seven benzodiazepines (clonazepam, flurazepam, alprazolam, midazolam, medazepam, chlordiazepoxide, and diazepam) and Amfepramone in slimming formulations that have been commercialized in Brazil. This method permits the screening of adulterant classes in a single voltammetric run by using a hanging mercury drop electrode as a working electrode and Ringer buffer (pH 10.0) as a supporting electrolyte. Recovery values ranging from 92.0% to 117.0% demonstrate the reliability of the method in the determination of adulterants in real samples. Among the 12 samples studied by the proposed method, 4 were demonstrated to be adulterated by 1,4-benzodiazepines.
Denise Bohrer - One of the best experts on this subject based on the ideXlab platform.
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A new method for the simultaneous determination of 1,4-benzodiazepines and Amfepramone as adulterants in phytotherapeutic formulations by voltammetry.
Forensic science international, 2010Co-Authors: Leandro M. De Carvalho, Daniele Correia, Solange C Garcia, André V De Bairros, Paulo C Do Nascimento, Denise BohrerAbstract:The use of synthetic pharmaceuticals in phytotherapeutics can be defined as an illegal practice, since these compounds are normally present as non-declared compounds in the phytotherapeutical formulations. This work aims to show the development of an analytical method based on adsorptive cathodic stripping voltammetry (AdCSV) for the simultaneous determination of 1,4-benzodiazepines and Amfepramone. The developed method was used to measure seven benzodiazepines (clonazepam, flurazepam, alprazolam, midazolam, medazepam, chlordiazepoxide, and diazepam) and Amfepramone in slimming formulations that have been commercialized in Brazil. This method permits the screening of adulterant classes in a single voltammetric run by using a hanging mercury drop electrode as a working electrode and Ringer buffer (pH 10.0) as a supporting electrolyte. Recovery values ranging from 92.0% to 117.0% demonstrate the reliability of the method in the determination of adulterants in real samples. Among the 12 samples studied by the proposed method, 4 were demonstrated to be adulterated by 1,4-benzodiazepines.
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Determination of synthetic pharmaceuticals in phytotherapeutics by capillary zone electrophoresis with contactless conductivity detection (CZE-C4D)
Microchemical Journal, 2010Co-Authors: Leandro M. De Carvalho, Mariele Martini, Ana Paula L. Moreira, Solange Cristina Garcia, Paulo C. Do Nascimento, Denise BohrerAbstract:Abstract In this work, a method for simultaneous determination of Amfepramone, fenproporex, sibutramine and fluoxetine was developed by capillary zone electrophoresis with capacitively coupled contactless conductivity detection (C4D) using a homemade capillary electrophoretic system. The optimized conditions for the separation of the pharmaceuticals by CZE were as follows: 50 mmol L− 1 phosphate buffer (pH 5.0) in 50/50 (v/v) mixture of water/acetonitrile as the working electrolyte, 15 kV separation voltage, 25 °C separation temperature, hydrodynamic injection by gravity using 20 cm injection height and 60 s injection time. The detection by C4D was carried out by using a homemade detector, which employs a sinusoidal wave generator operating at 600 kHz frequency and 2 Vpp wave amplitude. The optimized and validated CZE-C4D method was applied for the determination of the studied pharmaceuticals as adulterants in phytotherapeutic formulations commercialized in Brazil for slimming purposes.
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Voltammetric behavior of Amfepramone (diethylpropion) at the hanging mercury drop electrode and its analytical determination in pharmaceutical formulations
Journal of the Brazilian Chemical Society, 2007Co-Authors: Leandro M. De Carvalho, Paulo Cícero Do Nascimento, Denise Bohrer, Daniele Correia, André Valle De Bairros, Valdeci J. Pomblum, Solange Garcia PomblumAbstract:This paper describes a systematic study of the voltammetric behavior of Amfepramone at the hanging mercury drop electrode (HMDE) by cyclic (CV) and alternating current (AC) voltammetric methods. The studies showed the adsorptive behavior of Amfepramone at the HMDE and were performed in H2SO4 0.1 mol L-1 (pH 1.0) and Ringer buffer (pH 11.0) as supporting electrolytes. The linear range for the Amfepramone determination by differential pulse voltammetry (DPV) was 0.05 to 2.0 mg L-1 (r = 0.998) in acidic medium and 0.25 to 4.0 mg L-1 (r = 0.994) in alkaline medium. The relative standard deviation calculated was 2.5% and 4.0 % for five measurements of 0.5 mg L-1 Amfepramone in acidic and alkaline medium, respectively. The detection limits calculated for the Amfepramone determination in acidic and alkaline medium were 0.035 e 0.18 mg L-1, respectively.The methods were applied for the determination of Amfepramone by DPV in tablets and capsules of pharmaceutical formulations used in the treatment of obesity. Recoveries values ranging from 90.0 to 101.0% for Amfepramone added to synthetic mixtures containing fenproporex, mazindol, sibutramine, fluoxetine, caffeine, diazepam, and metformin as interferents prove the applicability of the method for its determination in the presence of other drugs normally added illegally to pharmaceutical formulations commercialized as natural medicaments.
Lisa L Ioannides-demos - One of the best experts on this subject based on the ideXlab platform.
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Pharmacotherapies for Obesity: Past, Current, and Future Therapies
Journal of Obesity, 2010Co-Authors: Lisa L Ioannides-demos, Loretta Piccenna, John J McneilAbstract:Past therapies for the treatment of obesity have typically involved pharmacological agents usually in combination with a calorie-controlled diet. This paper reviews the efficacy and safety of pharmacotherapies for obesity focusing on drugs approved for long-term therapy (orlistat), drugs approved for short-term use (Amfepramone [diethylpropion], phentermine), recently withdrawn therapies (rimonabant, sibutamine) and drugs evaluated in Phase III studies (taranabant, pramlintide, lorcaserin and tesofensine and combination therapies of topiramate plus phentermine, bupropion plus naltrexone, and bupropion plus zonisamide). No current pharmacotherapy possesses the efficacy needed to produce substantial weight loss in morbidly obese patients. Meta-analyses support a significant though modest loss in bodyweight with a mean weight difference of 4.7 kg (95% CI 4.1 to 5.3 kg) for rimonabant, 4.2 kg (95% CI 3.6 to 4.8 kg) for sibutramine and 2.9 kg (95% CI 2.5 to 3.2 kg) for orlistat compared to placebo at ≥12 months. Of the Phase III pharmacotherapies, lorcaserin, taranabant, topiramate and bupropion with naltrexone have demonstrated significant weight loss compared to placebo at ≥12 months. Some pharmacotherapies have also demonstrated clinical benefits. Further studies are required in some populations such as younger and older people whilst the long term safety continues to be a major consideration and has led to the withdrawal of several drugs.
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Review Article Pharmacotherapies for Obesity: Past, Current, and Future Therapies
2010Co-Authors: Lisa L Ioannides-demos, Loretta Piccenna, John J McneilAbstract:Copyright © 2011 Lisa L. Ioannides-Demos et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Past therapies for the treatment of obesity have typically involved pharmacological agents usually in combination with a caloriecontrolled diet. This paper reviews the efficacy and safety of pharmacotherapies for obesity focusing on drugs approved for longterm therapy (orlistat), drugs approved for short-term use (Amfepramone [diethylpropion], phentermine), recently withdrawn therapies (rimonabant, sibutamine) and drugs evaluated in Phase III studies (taranabant, pramlintide, lorcaserin and tesofensine and combination therapies of topiramate plus phentermine, bupropion plus naltrexone, and bupropion plus zonisamide). No current pharmacotherapy possesses the efficacy needed to produce substantial weight loss in morbidly obese patients. Metaanalyses support a significant though modest loss in bodyweight with a mean weight difference of 4.7 kg (95 % CI 4.1 to 5.3 kg) for rimonabant, 4.2 kg (95 % CI 3.6 to 4.8 kg) for sibutramine and 2.9 kg (95 % CI 2.5 to 3.2 kg) for orlistat compared to placebo at ≥12 months. Of the Phase III pharmacotherapies, lorcaserin, taranabant, topiramate and bupropion with naltrexone have demonstrated significant weight loss compared to placebo at ≥12 months. Some pharmacotherapies have also demonstrated clinical benefits. Further studies are required in some populations such as younger and older people whilst the long term safety continues to be a major consideration and has led to the withdrawal of several drugs. 1
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Safety of Drug Therapies Used for Weight Loss and Treatment of Obesity
Drug Safety, 2006Co-Authors: Lisa L Ioannides-demos, Joseph Proietto, Andrew M. Tonkin, John J McneilAbstract:Some of the medications used for weight loss in the management of obesity have been associated with unacceptable morbidity and mortality. Safety concerns have led to the withdrawal of aminorex, followed by the fenfluramines in 1997, and phenylpropanolamine (norephedrine) in 2000. Aminorex was associated with an increased prevalence of primary pulmonary hypertension (PPH), fenfluramines with an increased prevalence of PPH and valvulopathy, and phenylpropanolamine with an increased risk of haemorrhagic stroke. Several studies have investigated the safety of the fenfluramines, yet the benefit-risk profile has not been conclusively quantified. This is due to several deficiencies in the published studies, including a lack of data on the baseline prevalences of comorbid conditions in obese subjects, and potential confounders and biases in the study designs. Although several studies and systematic reviews support an increased risk of PPH and valvulopathy in patients who have taken fenfluramines, without knowledge of the background prevalence it is not possible to determine if the exposure preceded the outcome. The population at higher risk of these adverse effects includes those taking higher doses or with a longer duration of exposure to fenfluramines and those with pre-existing cardiac disease or a genetic predisposition. Patients exposed to fenfluramines continue to be monitored, with some follow-up studies indicating no overall worsening in valvulopathy over time. There are limited efficacy and safety data for Amfepramone (diethylpropion) and phentermine and their approval for the management of obesity is limited to short-term use. Orlistat and sibutramine are the only currently approved medications for long-term management of obesity. Although the benefit-risk profiles of sibutramine and orlistat appear positive, sibutramine continues to be monitored because of long-term safety concerns. The safety and efficacy of currently approved drug therapies have not been evaluated in children and elderly patient populations and there is limited information in adolescents, whilst the long-term safety of current and potential new drug therapies in adults will require several years of postmarketing surveillance to fully elucidate their adverse effect profiles.
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Pharmacotherapy for obesity
Drugs, 2005Co-Authors: Lisa L Ioannides-demos, Joseph Proietto, John J McneilAbstract:Pharmacotherapy for the management of obesity is primarily aimed at weight loss, weight loss maintenance and risk reduction, and has included thyroid hormone, amphetamines, phentermine, Amfepramone (diethylpropion), phenylpropanolamine, mazindol, fenfluramines and, more recently, sibutramine and orlistat. These agents decrease appetite, reduce absorption of fat or increase energy expenditure.
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Pharmacotherapy for Obesity
Drugs, 2005Co-Authors: Lisa L Ioannides-demos, Joseph Proietto, John J McneilAbstract:Pharmacotherapy for the management of obesity is primarily aimed at weight loss, weight loss maintenance and risk reduction, and has included thyroid hormone, amphetamines, phentermine, Amfepramone (diethylpropion), phenylpropanolamine, mazindol, fenfluramines and, more recently, sibutramine and orlistat. These agents decrease appetite, reduce absorption of fat or increase energy expenditure. Primary endpoints used to evaluate anti-obesity drugs most frequently include mean weight loss, percentage weight loss and proportion of patients losing ≥5% and ≥10% of initial body weight. Secondary endpoints may include reduction in body fat, risk factors for cardiovascular disease and the incidences of diseases such as diabetes mellitus. Most pharmacotherapies have demonstrated significantly greater weight loss in patients on active treatment than those receiving placebo in short-term (≤1 year) randomised controlled trials of pharmacological treatment in conjunction with a calorie-controlled diet or lifestyle intervention. The evidence of long-term efficacy is limited to sibutramine (2 years) and orlistat (4 years). These are the only drugs currently approved for the long-term management of obesity in adults. Sibutramine recipients randomised following 6 months’ treatment to either sibutramine or placebo demonstrated significantly better weight maintenance at 2 years than those taking placebo (p < 0.001), with ≥10% loss of initial bodyweight in 46% of patients. For patients taking orlistat, weight loss was 2.2kg greater than those on placebo at 4 years (p < 0.001), with significantly more patients achieving ≥10% loss of initial bodyweight (26.2% and 15.6%, respectively; p < 0.001). Other drugs that have been evaluated for weight loss include ephedrine, the antidepressants fluoxetine and bupropion, and the antiepileptics topiramate and zonisamide. Two clinical trials with fluoxetine both reported no significant difference in weight loss compared with placebo at 52 weeks. Clinical trials evaluating ephedrine, bupropion, topiramate and zonisamide have demonstrated significantly greater weight loss than placebo but have been limited to 16–26 weeks’ treatment. A major obstacle to the evaluation of the clinical trials is the potential bias resulting from low study completion rates. Completion rates varied from 52.8% of phentermine recipients in a 9-month study, to 40% of fenfluramine recipients in a 24-week comparative study with phentermine and 18% of Amfepramone recipients in a 24-week study. One-year completion rates range from 51% to 73% for sibutramine and from 66% to 85% for orlistat. Other potential sources of bias include run-in periods and subsequent patient selection based on compliance or initial weight loss. Several potential new therapies targeting weight loss and obesity through the CNS pathways or peripheral adiposity signals are in early phase clinical trials. Over the next decade the drug treatment of obesity is likely to change significantly because of the availability of new pharmacotherapies to regulate eating behaviours, nutrient partitioning and/or energy expenditure.