Obesity and overweight are reaching global epidemic proportions affecting more than 1.1 billion individuals worldwide. Excess weight is associated with an increased mortality, chronic morbidity (including type 2 diabetes, arterial hypertension, cardiovascular diseases, and certain cancers), decreased quality of life, and considerable health care costs (1).
Antiobesity drugs work through different mechanisms either in the central nervous system (CNS) or in the peripheral tissues. These mechanisms include: 1) suppression of food intake in the CNS, 2) decreased gut absorption of nutrients, and 3) increased energy expenditure or oxidation of nutrients. The efficacy of antiobesity drugs should be evaluated by their ability to reduce fat stores (preferentially visceral adipose tissue), maintain weight loss, diminish obesity-related health risks, and thus decrease morbidity and mortality, and improve quality of life. An ideal antiobesity drug should be administered orally, devoid of major side effects, and distributed at affordable price. Treatment with antiobesity drugs can be considered in obese patients who failed to achieve a sufficient weight loss to a program of lifestyle change, diet, and physical activity. However, the drug treatment of obesity should be an integral part of the comprehensive obesity treatment program that includes diet, exercise, and cognitive behavioral intervention (2,3). Treatment of obesity should be individually tailored taking into account the degree and character of obesity, age, sex, and the presence of comorbidities (4). Drugs used for the treatment of obesity in the past were associated with serious side effects (psycho-stimulatory, depression, addiction, cardio-excitatory effects, pulmonary hypertension, and valve disease). Antiobesity agents that possess cardio-excitatory and psycho-stimulatory effects (e.g., phentermine, ephedrine, and caffeine mixture) have still been available for the short-term use in some countries (<3 months).
SIBUTRAMINE AND ORLISTAT
Currently, only two drugs, sibutramine and orlistat, are prescribed for long-term administration. The most important trial evaluating the long-term efficacy of …