Weight and blood pressure response to weight management and sibutramine in diabetic and non-diabetic high-risk patients: an analysis from the 6-week lead-in period of the sibutramine cardiovascular outcomes (SCOUT) trial

Unapproved Pharmaceutical Ingredients Included in Dietary Supplements Associated With US Food and Drug Administration Warnings

IMPORTANCE

Over half of adults in the United States report consuming dietary supplements. The US Food and Drug Administration (FDA) has warned of numerous dietary supplements containing undeclared, unapproved pharmaceutical ingredients. These FDA warnings have not been comprehensively analyzed for recent years.

OBJECTIVE

To summarize trends across adulterated (containing unapproved ingredients) dietary supplements associated with a warning released by the FDA from 2007 through 2016.

DESIGN, SETTING, AND PARTICIPANTS

In this quality improvement study, data were extracted from the FDA's Center for Drug Evaluation and Research, Tainted Products Marketed as Dietary Supplements_CDER database from 2007 through 2016. Data from each warning were recorded unless multiple warnings were issued for the same product within a 6-month period. Date, product name, company, hidden ingredient(s), product category, source of sample, and warning document type were recorded for each included warning. Data analysis was conducted from February 2017 to June 2017.

RESULTS

From 2007 through 2016, 776 adulterated dietary supplements were identified by the FDA and 146 different dietary supplement companies were implicated. Most of these products were marketed for sexual enhancement (353 [45.5%]), weight loss (317 [40.9%]), or muscle building (92 [11.9%]), with 157 adulterated products (20.2%) containing more than 1 unapproved ingredient. The most common adulterants were sildenafil for sexual enhancement supplements (166 of 353 [47.0%]), sibutramine for weight loss supplements (269 of 317 [84.9%]), and synthetic steroids or steroid-like ingredients for muscle building supplements (82 of 92 [89.1%]). There were 28 products named in 2 or 3 warnings more than 6 months apart. Of these products, 19 (67.9%) were reported to contain new unapproved ingredients in the second or third warning, consistent with the assumption that the FDA found the product to be adulterated more than once. In recent years (2014-2016), 117 of 303 adulterated samples (38.6%) were identified through online sampling and 104 of 303 (34.3%) were identified through the examination of international mail shipments.

CONCLUSIONS AND RELEVANCE

Active pharmaceuticals continue to be identified in dietary supplements, especially those marketed for sexual enhancement or weight loss, even after FDA warnings. The drug ingredients in these dietary supplements have the potential to cause serious adverse health effects owing to accidental misuse, overuse, or interaction with other medications, underlying health conditions, or other pharmaceuticals within the supplement.

Assessment of potential cardiovascular risks of methylphenidate in comparison with sibutramine: do we need a SCOUT (trial)?

With the recent approval of methylphenidate (MPH) for treating attention-deficit/hyperactivity disorder (ADHD) in adults, the number of patients exposed will increase tremendously. The ongoing debate on the cardiovascular safety of MPH has triggered two large retrospective cohort studies in children and adolescents as well as in young to middle-aged adults. These studies looked into serious cardiovascular events (sudden cardiac death, acute myocardial infarction and stroke) as primary endpoints and concluded that MPH was safe after a mean duration of 2.1 years of follow-up in children and adolescents and mean duration of 0.33 years of current use in adults. The results are encouraging with respect to the short- and medium-term use of MPH. Without the inherent limitations of retrospective cohort studies, a prospective randomized, double-blind, placebo-controlled, multicenter trial in individuals stratified for cardiovascular risk factors would allow for an optimized risk assessment. With many millions of patients treated per year and drawing parallels to the lately discovered risks of sibutramine, another sympathomimetic with an overlapping mode of action and similar side effects on heart rate and blood pressure, we hypothesize that such a trial might be a dedicated risk mitigation strategy for public health. A critical assessment of cardiovascular side effects of MPH appears particularly warranted, because ADHD is associated with obesity, smoking and poor health in general. We summarize recent findings with the focus on cardiovascular risks of MPH in humans; we additionally analyze the limited number of rodent studies that have addressed cardiovascular risks of MPH.

Metabolic syndrome, hypertension, and diabetes mellitus after gastric banding: the role of aging and of duration of obesity

BACKGROUND

Bariatric surgery leads to resolution of arterial hypertension and diabetes mellitus; isolated reports indicate that response to bariatric surgery is lower in aged patients. The aim of this study was to evaluate the role of age and of duration of obesity on the frequency of co-morbidities in morbid obesity, as well as on improvement of co-morbidities.

METHODS

A total of 837 consecutive patients with known duration of obesity, undergoing gastric banding, were considered for this study; they were divided into quartiles of age and of duration of obesity. Presence of co-morbidities (diabetes mellitus, arterial hypertension, metabolic syndrome), metabolic variables (cholesterol and HDL-C, triglycerides, blood glucose), anthropometric variables, and loss of weight during 24 months were considered.

RESULTS

Older patients had a higher frequency of co-morbidities; duration of obesity only affected frequency of co-morbidities, but not response to surgery. At logistic regression, duration of obesity had a moderate independent effect on the frequency of diabetes. Older patients lost less weight than younger patients, but diabetes mellitus and arterial hypertension improved to the same extent in patients of different ages, and metabolic syndrome disappeared more in older patients, associated with a greater decrease of blood glucose. Frequency of removal of gastric banding and loss to follow-up were not different in different quartiles of age or in different quartiles of duration of obesity.

CONCLUSION

Older patients, despite lower weight loss, have a response to bariatric surgery that is similar to that of younger patients; age and duration of obesity should not be considered as limits to indications to bariatric surgery.

Anti-obesity drugs: a review about their effects and their safety

INTRODUCTION

Amphetamines, rimonabant and sibutramine licenses as anti-obesity drugs have been withdrawn because of their adverse effects. In fact, orlistat is the only available long-term treatment for obesity.

AREAS COVERED

The efficacy and safety of long-term drug therapy is very important in the management obesity; for this reason, the authors decided to conduct a review on the efficacy and safety of current, past and future pharmacotherapies for weight loss.

EXPERT OPINION

Orlistat is a good choice for the treatment of obesity, because of its safety on cardiovascular events and its positive effects on diabetic control, even if it is not as effective as rimonabant or sibutramine in reducing body weight. Regarding emerging anti-obesity therapies in diabetic people, we currently have drugs that have already been marketed including the glucagon-like peptide-1 (GLP-1) receptor agonists exenatide and liraglutide; other than improving glycemic control, they also suppress appetite reducing body weight. Moreover, some other drugs are currently in study such as tesofensine, phentermine + topiramate, bupropion + naltrexone and bupropion + zonisamide. Furthermore, several additional gut hormone-based treatments for obesity are under investigation in Phase II and III clinical trials, with particular focus on ghrelin, peptide YY, pancreatic polypeptide, amylin and oxyntomodulin.

Cardiovascular risk-benefit profile of sibutramine

Sibutramine is a combined norepinephrine and serotonin reuptake inhibitor used as an antiobesity agent to reduce appetite and promote weight loss in combination with diet and exercise. At a daily dose of 10-20 mg, it was initially considered to have a good safety profile, as it does not induce primary pulmonary hypertension or adverse effects on cardiac valves, in contrast to previous reports relating to some other antiobesity agents. However, it exerts disparate effects on cardiovascular risk factors. On the one hand, sibutramine may have antiatherogenic activities, as it improves insulin resistance, glucose metabolism, dyslipidemia, and inflammatory markers, with most of these effects resulting from weight loss rather than from an intrinsic effect of the drug. On the other hand, because of its specific mode of action, sibutramine exerts a peripheral sympathomimetic effect, which induces a moderate increase in heart rate and attenuates the reduction in BP attributable to weight loss or even slightly increases BP. It may also prolong the QT interval, an effect that could induce arrhythmias. Because of these complex effects, it is difficult to conclude what the final impact of sibutramine on cardiovascular outcomes might be. Sibutramine has been shown to exert favorable effects on some surrogate cardiovascular endpoints such as reduction of left ventricular hypertrophy and improvement of endothelial dysfunction. A good cardiovascular safety profile was demonstrated in numerous 1- to 2-year controlled trials, in both diabetic and nondiabetic well selected patients, as well as in several observational studies. However, since 2002, several cardiovascular adverse events (hypertension, tachycardia, arrhythmias, and myocardial infarction) have been reported in sibutramine-treated patients. This led to a contraindication of the use of this antiobesity agent in patients with established coronary heart disease, previous stroke, heart failure, or cardiac arrhythmias. SCOUT (Sibutramine Cardiovascular and Diabetes Outcome Study) was designed to prospectively evaluate the efficacy/safety ratio of sibutramine in a high-risk population. The efficacy/safety results of the first 6-week lead-in open period of treatment with sibutramine 10 mg/day were reassuring in 10 742 overweight/obese high-risk subjects (97% had cardiovascular disease, 88% had hypertension, and 84% had type 2 diabetes mellitus). However, the final results of SCOUT showed that long-term (5 years') treatment with sibutramine (10-15 mg/day) exposed subjects with pre-existing cardiovascular disease to a significantly increased risk for nonfatal myocardial infarction and nonfatal stroke, but not cardiovascular death or all-cause mortality. Because the benefit of sibutramine as a weight-loss aid seems not to outweigh the cardiovascular risks, the European Medicines Agency recommended the suspension of marketing authorizations for sibutramine across the EU. The US FDA stated that the drug should carry a 'black box' warning due to an increased risk of stroke and heart attack in patients with a history of cardiovascular disease. In conclusion, concern still persists about the safety profile of sibutramine regarding cardiovascular outcomes, and the drug should not be prescribed for overweight/obese patients with a high cardiovascular risk profile.

Blood Pressure-Lowering Aspects of Lipid-Lowering and Anti-Diabetic Drugs

Several studies have shown that blood pressure can be lowered by the use of drugs that are not traditional antihypertensive drugs. This might be of clinical importance when many risk patients are treated by combination drug therapy in order to prevent cardiovascular disease by way of improving the cardiovascular risk factor profile.

Pharmacotherapies for obesity: past, current, and future therapies

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.

No compelling evidence that sibutramine prolongs life in rodents despite providing a dose-dependent reduction in body weight

OBJECTIVE

The health and longevity effects of body weight reduction resulting from exercise and caloric restriction in rodents are well known, but less is known about whether similar effects occur with weight reduction from the use of a pharmaceutical agent such as sibutramine, a serotonin-norepinephrine reuptake inhibitor.

RESULTS AND CONCLUSION

Using data from a 2-year toxicology study of sibutramine in Sprague-Dawley CD rats and CD-1 mice, despite a dose-dependent reduction in food intake and body weight in rats compared with controls, and a body weight reduction in mice at the highest dose, there was no compelling evidence for reductions in mortality rate.