Update on pharmacology of obesity: benefits and risks.

The prevalence of obesity in Western countries has increased at a much greater pace than the development of new efficient and safe drugs, beyond mere lifestyle changes, for the treatment of overweight. Numerous different types of drugs which had been used in the past for the treatment of obesity have currently been withdrawn due to undesirable long-term side effects. The only available drug in Europe is orlistat, which serves only as an aid for the treatment of obesity. In the USA, however, a few central adrenergic-mediators, for instance, diethylpropion and phentermine, have been available for decades to treat obesity during a short-term period (less than 12 weeks). The Food and Drug Administration (FDA) has recently approved lorcaserin and the combination phentermine/ topiramate for the treatment of obesity. The first one is a selective serotonin 2C receptor agonist that works by decreasing food intake with few side effects. Its outcomes on weight are modest, but may be helpful in certain selected patients. The phentermine/topiramate combination has proved to be highly effective, achieving a 10% reduction in weight in the majority of patients, although attention must be drawn to the possible development of side effects in both the short and the long-term follow-up. Further investigation regarding the mechanisms involved in weight balance will anticipate the development of new expectations for the treatment of obesity in the near future.