Safety Assessment of an Anti-Obesity Drug (Sibutramine): A Retrospective Cohort Study

Effect of hyperbaric oxygen therapy on weight loss and hyperlipidemia in rats

OBJECTIVE

To explore whether hyperbaric oxygen therapy(HBO) can promote weight loss and recovery of hyperlipidemia in rats, and to explore the possible mechanism.

METHODS

180 SD rats were divided into 6 groups with 30 rats in each group. The first 3 groups were intraperitoneally injected with fat emulsion to make hyperlipidemia models, and the last three groups were injected with normal saline. The first three groups received 3 h/d, 6 h/d, 0 h/d HBO therapy respectively, and the last three groups received the same treatment. Body weight, blood lipid and transaminase were measured in all SD rats, and pathological sections of heart, liver and kidney were observed.

RESULTS

Hyperlipidemia group treated with 3 h/d hyperbaric oxygen has the effect of reducing hyperlipidemia compared with other groups and has the effect of heart and kidney protection. Although 6 h/d HBO therapy has a more noticeable effect on lowering hyperlipidemia, it has more apparent liver damage effects. The normal group treated with HBO for 3 h/d or 6 h/d both have the effect of weight loss, and the impact of liver injury is not apparent. However, the 6 h/d HBO therapy group had a more prominent weight loss effect.

CONCLUSION

HBO therapy can promote weight loss and reduce hyperlipidemia. Our experiments have shown that 6 h/d and 3 h/d HBO therapy reduces blood lipids in hyperlipidemia SD rats. However, the former has noticeable liver damage effects on SD rats, and the latter is adequate for protecting the liver in normal or hyperlipidemia SD rats. At the same time, it has been proved that HBO therapy has cardio and kidney protection in hyperlipidemia SD rats.

Clinical outcomes associated with anti-obesity medications in real-world practice: A systematic literature review

Anti-obesity medications (AOMs) are efficacious and well tolerated in randomized controlled trials, but findings may not be generalizable to routine clinical practice. This systematic literature review aimed to identify real-world (RW) evidence for AOMs to treat adults ( ≥ 18 years) with obesity or overweight (BMI  ≥  27 kg/m² ). Searches conducted in MEDLINE, Embase, Health Technology Assessment (HTA) Database, National Health Service (NHS) Economic Evaluation Database, and Cochrane Central Register of Controlled Trials for studies of relevant FDA-approved AOMs yielded 41 publications. Weight loss (WL) was consistently observed, with 14% to 58.6% of patients achieving ≥ 5% WL on orlistat, phentermine/topiramate, naltrexone/bupropion, phentermine, or liraglutide in studies of 3-6 months' duration where this was measured. When cardiometabolic risk factors were assessed, AOMs reduced or had no impact on blood pressure, lipids, or glycemia. RW data on the impact of AOMs on existing obesity-related comorbidities and mortality were generally lacking. AOMs were associated with various adverse events, but these were of mild to moderate severity and no unexpected safety signals were reported. A pattern of poor adherence and persistence with AOMs was observed across studies. Overall, the review confirmed the effectiveness of AOMs in RW settings but demonstrated large gaps in the evidence base.

Progress and challenges in anti-obesity pharmacotherapy

Obesity is a serious and growing worldwide health challenge. Healthy lifestyle choices are the foundation of obesity treatment. However, weight loss can lead to physiological adaptations that promote weight regain. As a result, lifestyle treatment alone typically produces only modest weight loss that is difficult to sustain. In other metabolic diseases, pharmacotherapy is an accepted adjunct to lifestyle. Several anti-obesity drugs have been approved in the USA, European Union, Australia, and Japan including sympathomimetics, pancreatic lipase inhibitors, GABA_A receptor activators, a serotonin 2C receptor agonist, opioid antagonist, dopamine-norepinephrine reuptake inhibitor, and glucagon-like peptide-1 (GLP-1) receptor agonists. These drugs vary in their efficacy and side-effect profiles but all provide greater weight loss than do lifestyle changes alone. Even though obesity is widespread and associated with adverse health consequences, and anti-obesity drugs can help people to lose weight, very few patients use these drugs partly because of concerns about safety and efficacy, but also because of inadequate health insurance coverage. Despite great advances in our understanding of the biology of weight regulation, many clinicians still believe that patients with obesity should have the willpower to eat less. The tendency to hold the patient with obesity responsible for their condition can be a barrier to greater acceptance of anti-obesity drugs as appropriate options for treatment. Physicians should be comfortable discussing the risks and benefits of these drugs, and health insurance companies should provide reasonable coverage for their use in patients who are most likely to benefit. Although few promising anti-obesity medications are in the drug-development pipeline, the most promising drugs are novel molecules that are co-agonists for multiple gut hormones including GLP-1, glucagon, and gastric inhibitory peptide.

Analytical Methodologies for the Stereoselective Determination of Sibutramine: An Overview

Sibutramine is a chiral anti-obesity drug which decreases food intake and increases energy expenditure. In therapy it is used as a racemic mixture; however both pharmacokinetic and pharmacodynamic data have revealed enantioselective behavior of sibutramine and its major active metabolites. Several chromatographic and electrophoretic analytical methods have been published so far for the chiral determination of sibutramine from pharmaceutical preparations and biological samples. The current paper aims to provide a systematic review of the stereochemical aspects and analytical methods used for the enantiodetermination of sibutramine and its active enantiomers covering the last 15 years.

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.

Effects of oral anorexiant sibutramine on the expression of cytochromes P450s in human hepatocytes and cancer cell lines

Sibutramine is a serotonin-norepinephrine reuptake inhibitor that was used for weight-loss management in obese patients. Even though it was officially withdrawn from the market in 2010, it is still present in some tainted weight-loss pills (as reported by US Food and Drug Administration). Thus, it is still reasonable to study the effects of this compound. The aim of this work was to investigate the potential of sibutramine to induce CYP1A1/CY3A4 in human cancer cell lines and CYP1A1/2, CYP2A6, CYP2B6, and CYP3A4 in human hepatocytes, a competent model of metabolically active cells. The levels of mRNA and protein of CYP1A1/1A2/3A4/2A6/2B6 were compared with the typical inducers, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and rifampicin (RIF) for CYP1A1/2 and for other CYPs, respectively. The mRNA and protein levels of all genes in either cancer cell lines or human hepatocytes were induced when treated with typical inducers but not with sibutramine.