Drug therapy for obesity in the elderly

The prevalence of obesity is increasing rapidly in the US and other developed countries. Even though the percentage of older individuals is increasing worldwide, obesity has only recently become a recognised problem in this population. Obesity occurs when energy intake chronically exceeds energy expenditure. Moreover, advancing age is associated with an inability to couple energy intake with energy expenditure. Obesity contributes to many adverse health outcomes, including non-insulin-dependent (type II) diabetes mellitus, as well as to an increase in both cardiovascular and all-cause mortality. Only recently has the medical community begun to accept obesity as a disease with a multifactorial pathogenesis that requires systematic lifestyle changes and pharmacological treatment. Several groups of drugs are available for the pharmacotherapy of obesity; anorectic medications (e.g. fenfluramine, dexfenfluramine); substances affecting energy expenditure and body composition [e.g. chromium (chromium picolinate), ephedrine, anabolic steroids, beta 3-adrenoceptor agonists]; and drugs affecting the absorption of nutrients (e.g. orlistat). To date, few drugs have produced and sustained a significant bodyweight loss. However, some drugs induce a significant short term reduction in bodyweight compared with placebo. Moreover, there is a paucity of information regarding the effectiveness of these drugs in the treatment of obesity in the elderly. Furthermore, it is even debated whether obesity should be treated with drug intervention in the elderly. Clinicians prescribing medications for obesity treatment in the elderly need to carefully consider the benefit: risk ratio, given the high prevalence of polypharmacy in elderly patients. Furthermore, physiological changes that occur with aging may affect the pharmacokinetics of administered drugs and need to be taken into consideration.