Use of drugs in the treatment of obesity.

Obesity has become an epidemic in the United States and in many other countries of the world. Obesity is a chronic disease, not a failure of willpower. Diet, exercise, and behavioral modification of lifestyle are rarely successful over the long term. Medications have been used sparingly, because of concerns about addiction and ineffectiveness, but used chronically, obesity drugs are effective. The two main categories of obesity drugs are centrally active adrenergic and serotonergic agents. These drugs reduce appetite, enhance satiety, and increase energy expenditure. Use of single agents produces modest weight loss and use of combinations increases loss, but few patients reach their goal weight. Co-morbidities associated with obesity resolve or are reduced in severity with weight loss. Adverse events of major concern are changes in brain biochemistry and primary pulmonary hypertension. Published guidelines for use of obesity medications recommend they be used only for medically significant obesity.