Sibutramine

Sibutramine is a drug, originally used in the treatment of depression, which is now used to help obese and overweight patients lose weight, and along with Orlistat, in 2008 was the only drug licensed for use in the UK. It acts within the hypothalamus by preventing reuptake of both noradrenaline and serotonin. This inhibition causes the patient increased feelings of satiety, a decreased appetite, and a corresponding reduced intake of food which results in weight loss. Some studies have shown that sibutramine may increase thermogenesis and as such, contribute to weight loss, but there have also been other studies in which no such effects were shown, and it seems that this action contributes in, at most a minor way to weight loss. It is also thought that sibutramine may effect levels of the hormones leptin and ghrelin, as well as central neuropeptide Y (NPY), and proopiomelanocortin (POMC) mRNA. Sibutramine treatment differs to orlistat in relation to leptin, as, when using sibutramine, transfer of leptin into the brain is maintained or even increased during weight loss which does not happen when using orlistat.