Drug therapy in the elderly.

This review examines altered drug responses during aging. The incidence of diseases and disorders that require drug treatment rapidly increases with advancing age; elderly patients tend to receive more medications more often and are therefore at a correspondingly higher risk of experiencing adverse drug reactions and interactions. The cognitive decline that commonly accompanies aging can exacerbate this problem, with elderly individuals becoming confused and forgetful about their prescribed medications. Physiological responses to drugs depend on several factors, including the time course of drug absorption, distribution, metabolism, and elimination in the body (pharmacokinetics), and the actions of these drugs at the intracellular level (pharmacodynamics). As people age, the pathophysiologic processes of aging will influence all of these factors, including the time course of drug concentration in the body and target organ sensitivity. These age-related pharmacokinetic and pharmacodynamic effects must always be kept in mind by those responsible for the medical care of the elderly.