Novel anti-obesity drugs

There is increasing evidence that body weight is homeostatically regulated and that in obesity this regulation maintains weight at a high level. Weigh t loss activates mechanisms that are designed to return individuals to thei r pre-existing weight. This explains the universally poor results of curren t strategies to maintain weight loss. On this basis, life-long drug therapy may be justified for those with significant obesity. Currently available d rugs include selective serotonin re-uptake inhibitors (e.g., fluoxetine), n oradrenergic re-uptake inhibitors (e.g., phentermine), a serotonin and nora drenergic re-uptake inhibitor (sibutramine) and an intestinal lipase inhibi tor (orlistat). An active research program is underway to develop new agent s based on the rapidly expanding knowledge of the complex mechanisms regula ting body weight. Leptin, a hormone produced by adipocytes that inhibits fo od intake, has undergone clinical trials and analogues are currently being developed. Other agents include amylin, melanocortin-4 receptor agonists, n europeptide Y antagonists, PS adrenergic agonists and glucagon-like peptide -1 agonists. As some redundancy exists in the central regulatory system con trolling body weight, some agents might need to be used in combination to b e effective.