Pharmacological Therapies of Obesity: A Review of Current Treatment Options

Over the last decade, the incidence of overweight and obesity has nearly doubled in many countries and is considered a pandemic. Obesity was identified as a major risk factor for cardiovascular disease as the same level as smoking and diabetes. Visceral fat is considered one of the key contributors to outcome and certain ethnic groups such as Asians seem to be more affected than others. Weight reduction through lifestyle changes was found to be impactful to improve overall health, but weight loss and maintenance thereof is limited and difficult to sustain. Surgical intervention demonstrated a greater weight loss in the severely obese and was associated with improved all-cause mortality. Despite numerous pharmacological targets and a high medical need, only few drugs have been successfully developed. Earlier studies with amphetamine-derived compounds showed significant weight loss but their critical safety profiles led to market withdrawals and disappointment. More recent compounds; orlistat - a lipase inhibitor, rimonabant - a cannaboid-1-receptor antagonist, and sibutramine - a combined serotonin/norepinephrine re-uptake inhibitor, all demonstrated similar significant efficacy; however, they carry specific safety profiles making them unsuitable for every patient. The main limitation of pharmacotherapy is the absence of clear benefit-risk assessments through outcome studies. Such a study - the SCOUT trial - was designed to compare sibutramine versus placebo and the effect on morbidity and mortality in nearly 10,000 obese patients with additional risk factors. Such studies could provide new scientific evidence for obesity treatment and may support future pharmacological approaches.