Pharmacological treatment of obesity. Past, present, and future

Physicians have struggled with the pharmacological treatment of obesity. In the past, thyroid hormone was often used inappropriately. Dangerous drugs such as dinitrophenol and amphetamines were prescribed, with serious side effects. In the 1980s, a 3 1/2-year study using antiobesity medications with different mechanisms of action supported the theory that patients treated with combination therapy experienced greater weight loss than the placebo-treated patients and that those who remained on therapy were more likely to keep the weight off. Thus, physicians began prescribing "fen-phen" to their patients in the mid-1990s. In 1997, manufacturers voluntarily withdraw the fenfluramines from the market after study results linked their use with valvular heart disease. Since then, two new drugs with different mechanisms of action have been approved for use by the FDA. Sibutramine (Meridia) is a serotonin-norepinephrine reuptake inhibitor acting on the appetite center in the hypothalamus, and orlistat (Xenical) is a pancreatic lipase inhibitor. Research on antiobesity drugs continues. More than 30 potentially new drugs are in various stages of research. It could be years, however, before any of them are proven useful and safe. Antiobesity pharmacology is meant to be used as a tool to treat the disease. Lifestyle changes in the form of diet and exercise patterns are still the crux of therapy.