Special Populations: Profiling the Effect of Obesity on Drug Disposition and Pharmacodynamics

Abstract

The health implications of obesity remain a global issue with approximately 13% of the world’s population categorized as obese (body mass index [BMI] ≥30 kg/m2) in 2016 (World Health Organization, Obesity and overweight. http://www.who.int/en/news-room/fact-sheets/detail/obesity-and-overweight. Accessed 8 Oct 2018, 2018). Obesity is typically a consequence of either excess food intake, lack of physical activity, genetic predisposition, or a combination thereof. Its impact is multifaceted, not only on the patient’s health leading to a myriad of disease states directly related to obesity, but also on the management of these diseases and other common medical conditions that frequently occur. Obesity-related changes in normal physiology, such as alterations in lipid content, plasma proteins, drug metabolizing enzymes, drug transporters, and blood flow, can affect the disposition (absorption, distribution, metabolism, and excretion) and pharmacodynamics of commonly prescribed drugs, thereby altering their pharmacologic profiles. Hence, an understanding of these pharmacologic changes is necessary to ensure proper treatment is exercised. Unfortunately, our understanding of obesity-related changes in drug pharmacology in addition to the overall safety and efficacy is limited, as clinical trials rarely focus specifically on this population. Therefore, the purpose of this chapter is to provide a review of the available literature assessing the effects of obesity on the disposition and pharmacodynamics of some of the most commonly prescribed drugs. This chapter is a review only; careful clinical decision making should always be used when applying literature from the population to individual patients and scenarios.