Thermogenic drugs as a strategy for treatment of obesity.

There is accumulating evidence to support the hypothesis that a low-energy-output phenotype is at high risk of weight gain and obesity, irrespective of whether this is owing to a low resting metabolic rate and/or physical inactivity. The low-energy-output phenotype is associated with impaired appetite control, which is improved if energy output is increased. This is the background for pharmacologic stimulation of energy expenditure as a tool to improve the results of obesity management. Targets are the leptin receptors, the sympathetic nervous system and its peripheral beta-adrenoceptors, selective thyroid hormone derivatives, and stimulation of the mitochondrial uncoupling proteins. Currently available compounds such as recombinant leptin, ephedrine/caffeine, and sibutramine possess thermogenic properties owing to their activation of the sympathoadrenal system. Compounds acting selectively on the human beta3-adrenoceptor are still promising tools to achieve a sustained stimulation of lipolysis and energy expenditure, and several are in the pipeline.