Although the term “personalized medicine” has been associated in many cases with pharmacogenomics, its definition embraces the use of specific biomarkers and covariates to help in the selection of medical treatments and procedures which are best for each patient. While several efforts have been performed for the tailored selection of therapies and dosing regimens in the general population, developing personalized medicine initiatives for elderly patients remains understudied. The personalized drug therapy for older patients requires the consideration of anatomical, physiological and functional alterations in a multimorbid setting requiring multiple medications. The present review focuses on currently employed qualitative and quantitative precision medicine approaches for elderly patients and discusses some of the associated challenges and limitations. Furthermore, the use of and confidence in physiologically-based approaches for optimal dose selection in this understudied yet clinically important patient population will be highlighted and discussed.