ATC Group: A08A Antiobesity preparations, excl. diet products

Amfepramone is a sympathomimetic amine with some pharmacologic activity similar to that of the prototype drugs of this class used in obesity, the amphetamines. Actions include some central nervous system stimulation and elevation of blood pressure. It has not been established, however, that the action of such drugs in treating obesity is primarily one of appetite suppression. For example, other central nervous system actions or metabolic effects may be involved.

The exact neurochemical appetite suppressant effects of naltrexone/bupropion are not fully understood. Naltrexone is a mu-opioid antagonist and bupropion, a weak inhibitor of neuronal dopamine and norepinephrine reuptake. These components affect two principal areas of the brain, specifically the arcuate nucleus of the hypothalamus and the mesolimbic dopaminergic reward system.

Clobenzorex is an N-substituted amphetamine analog that is converted to d-amphetamine soon after ingestion. Clobenzorex is a stimulant drug of the phenethylamine and amphetamine chemical classes used as an appetite suppressant.

Dexfenfluramine is the d-enantiomer of fenfluramine (structurally similar to amphetamine) and acts as a serotonergic anorectic drug that reduces appetite by increasing the amount of extracellular serotonin in the brain.

Fenfluramine is a serotonin releasing agent, and thereby stimulates multiple 5-HT receptor sub-types through the release of serotonin. Fenfluramine may reduce seizures by acting as an agonist at specific serotonin receptors in the brain, including the 5-HT1D, 5-HT2A, and 5-HT2C receptors, and also by acting on the sigma-1 receptor. The precise mode of action of fenfluramine in Dravet syndrome and Lennox-Gastaut syndrome is not known.

Lorcaserin is believed to decrease food consumption and promote satiety by selectively activating 5-HT_2C receptors on anorexigenic pro-opiomelanocortin neurons located in the hypothalamus. The exact mechanism of action is not known. It is used as an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adult patients.

Mazindol is a sympathomimetic amine for the treatment of obesity and Duchenne muscular dystrophy. Like other sympathomimetic appetite suppressants, mazindol is thought to act as a reuptake inhibitor of norepinephrine. In addition, it inhibits dopamine and serotonin reuptake. It stimulates the central nervous system, which increases heart rate and blood pressure, and decreases appetite.

Mefenorex is an amphetamine derivative which was used as an appetite suppressant.

Orlistat is a potent, specific and long-acting inhibitor of gastrointestinal lipases. It exerts its therapeutic activity in the lumen of the stomach and small intestine by forming a covalent bond with the active serine site of the gastric and pancreatic lipases. The inactivated enzyme is thus unavailable to hydrolyse dietary fat, in the form of triglycerides, into absorbable free fatty acids and monoglycerides.

Rimonabant is a selective cannabinoid-1 receptor (CB1) antagonist that inhibits the pharmacological effects of cannabinoid agonists in vitro and in vivo. The endocannabinoid system is a physiological system present in brain and peripheral tissues (including adipocytes) that affects energy balance, glucose and lipid metabolism and body weight, and in neurons of the mesolimbic system modulates the intake of highly palatable, sweet or fatty foods.

Setmelanotide is a selective MC4 receptor agonist. MC4 receptors in the brain are involved in regulation of hunger, satiety, and energy expenditure. In genetic forms of obesity associated with insufficient activation of the MC4 receptor, setmelanotide is believed to re-establish MC4 receptor pathway activity to reduce hunger and promote weight loss through decreased caloric intake and increased energy expenditure.

Subitramine is a potent inhibitor of monoamines (serotonin, dopamine, noradrenaline) reuptake for the treatmen of obesity. Sibutramine is metabolized to metabolites M1 and M2 which are more active toward the monoamine transporters.