Effects of Aging on Pharmacokinetic and Pharmacodynamic Drug Processes

Howland, Robert H. MD, Section Editor
Howland, Robert H. MD

Dr. Howland is Associate Professor of Psychiatry, University of Pittsburgh School of Medicine, Western Psychiatric Institute and Clinic, Pittsburgh, Pennsylvania.

The author discloses that he has no significant financial interests in any product or class of products discussed directly or indirectly in this activity, including research support.

Address correspondence to Robert H. Howland, MD, Associate Professor of Psychiatry, University of Pittsburgh School of Medicine, Western Psychiatric Institute and Clinic, 3811 O'Hara Street, Pittsburgh, PA 15213; e-mail:[email protected]. doi:10.3928/02793695-20090902-06

Journal of Psychosocial Nursing & Mental Health Services 47(10):p 15-18, October 2009.

ABSTRACT

Aging affects the pharmacokinetics and pharmacodynamics of drugs, which has potentially important implications for the use of psychotropic medication in older adults. The absorption of orally administered drugs may be impaired or delayed, the volume of distribution of most drugs is decreased, and over time, the distribution shifts toward greater drug accumulation in fat stores. Decrease in renal function with age is especially important regarding the use of lithium but is also relevant for most drugs because they are eventually cleared through the kidneys after metabolism in the liver. Because pharmacodynamic changes associated with aging will make elderly patients more sensitive to the pharmacological effects of medication— especially adverse effects—nurses should be appropriately trained in pharmacology and therapeutics in older adults.