geriatrics
Pharmacokinetics in Older Adults
Introduction
 Overview of Pharmacokinetics is best defined as what the body does to the drug; it includes Absorption Distribution across body compartments Metabolism Excretion With aging, there are changes in all these areas; some changes are more clinically relevant. The metabolism and excretion of many drugs decrease, requiring that doses of some drugs be decreased. Toxicity may develop slowly because concentrations of chronically used drugs increase for 5 to 6 half-lives, until a steady state is achieved. For example, certain benzodiazepines (diazepam,flurazepam,chlordiazepoxide), or their active metabolites, have half-lives of up to 96 hours in older patients; signs of toxicity may not appear until days or weeks after therapy is started. 