Clinical trials are the most definitive tool for evaluation of the applica­ bility of clinical investigations. The main objective of clinical investiga­ tions is to assess the potential value of a therapeutic entity in the treat­ ment or prophylaxis of a disease or a condition. It is also deemed necessary at this stage to obtain information regarding the undesirable side effects, associated risks, and their interrelationship with clinical assessments. Most of these clinical investigations conform, in some form or fashion, to the guidelines adopted by the Food and Drug Administration (FDA) for a given class of compounds. Clinical investigations in the past have not included specific studies in special or subpopulations, e.g., the elderly. Because of an ever-increasing elderly population, newer policies for clinical investigations are now being debated with the recognition of enhanced drug sensitivity in this special population. This key research activity can lead not only to improved health care in the elderly but also to control of its costs.