Megestrol Acetate and Mirtazapine for the Treatment of Unplanned Weight Loss in the Elderly

A rising concern among clinicians is treatment of unplanned weight loss in the elderly, especially given the predicted growth of this population over the next few decades. Unexpected weight loss in the geriatric patient worsens overall health outcomes. A variety of pharmacotherapeutic options are available for treatment; however, evidence underlying their use is limited, and none has gained approval from the United States Food and Drug Administration for this indication. At present, no guidelines support the choice of one agent over another. Although several drug interventions have been employed for this problem, megestrol acetate and mirtazapine are becoming increasingly used for appetite stimulation. These drugs represent two feasible options for geriatric patients because of their generally favorable adverse‐effect profiles and few drug interactions, but they are often misused. In a comprehensive search of the MEDLINE and International Pharmaceutical Abstracts databases, we identified all published reports on the use of megestrol acetate or mirtazapine for the treatment of weight loss and on any adverse events associated with these drugs. Special emphasis was placed on trials performed in an elderly population. Results were conflicting, most likely because of differing study designs and small numbers of patients. Megestrol acetate and mirtazapine appear to be effective for appetite stimulation and weight gain in some settings. However, applicability of the data to elderly individuals is unclear, and adverse events reported in a few of the trials and in case reports were not benign. Therefore, the use of megestrol acetate or mirtazapine for weight loss should be thoroughly evaluated on an individual basis. Pharmacotherapy should be used only after all underlying causes of weight loss are assessed and treated.