Antiobesity therapy: emerging drugs and targets

Obesity and its associated morbidities and mortalities are the effects of imbalance between energy intake and expenditure. The healthcare burden for the treatment of obesity is significantly high, due to increased risk of secondary chronic diseases such as hypertension and associated co-morbidities such as diabetes and cardiovascular disease. Lack of physical activity, high fat diets and sedentary life styles are major factors contributing to obesity. However, genetic predisposition and ethnicity are increasingly found to cause obesity. Till date, approved therapeutics have addressed excess energy intake by acting on central neural circuits that regulate feeding or on peripheral mechanisms to reduce nutrient absorption from the gut. These approaches have met with moderate success; and recently with safety concerns, leaving an unmet medical need for effective and safe pharmacotherapy for obesity thereby posing a significant challenge to pharmaceutical industry. Potential antiobesity drugs, which are being investigated by different companies, can be classified in 4 broad categories: 1) Agents that primarily decrease appetite through central action; 2) Agents that primarily increase metabolic rate or affect metabolism through peripheral action; 3) Agents that act on gastrointestinal tract; and 4) Agents that not only affect obesity but also overall Metabolic Syndrome. The current review will deal mainly with different molecules, which are under development for the above-mentioned targets and also their potential benefits and disadvantages.