Geriatric drug evaluation: where are we now and where should we be in the future?

The older population is currently the fastest growing age group in the United States, and this trend is expected to continue for several decades. Older individuals, in general, have a higher disease burden compared with younger adults and are the major users of medications, yet premarketing drug clinical trials have often excluded them even for the drugs that have high utility in this age group. Extrapolation of clinical results from younger to older individuals does not provide adequate benefit-risk estimation, and the frequent need for dose adjustment in older patients from initially approved doses exemplifies the current lack of adequate clinical data in the elderly. Herein, we discuss the information gap for older individuals and the need for a better understanding of the effect of aging on drug responses. We also present cases for future directions, urging the implementation of improved clinical trial designs using new and emerging pharmacokinetic and pharmacodynamic methods to allow the provision of evidence-based individualized treatment to this high drug use group.